greenplumn indexcmds 源码

  • 2022-08-18
  • 浏览 (330)

greenplumn indexcmds 代码

文件路径:/src/backend/commands/indexcmds.c

/*-------------------------------------------------------------------------
 *
 * indexcmds.c
 *	  POSTGRES define and remove index code.
 *
 * Portions Copyright (c) 2005-2010, Greenplum inc
 * Portions Copyright (c) 2012-Present VMware, Inc. or its affiliates.
 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 *
 * IDENTIFICATION
 *	  src/backend/commands/indexcmds.c
 *
 *-------------------------------------------------------------------------
 */

#include "postgres.h"

#include "access/amapi.h"
#include "access/heapam.h"
#include "access/htup_details.h"
#include "access/reloptions.h"
#include "access/sysattr.h"
#include "access/tupconvert.h"
#include "access/tableam.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/index.h"
#include "catalog/indexing.h"
#include "catalog/pg_am.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_inherits.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_opfamily.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_type.h"
#include "commands/comment.h"
#include "commands/dbcommands.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/progress.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/optimizer.h"
#include "parser/parse_coerce.h"
#include "parser/parse_func.h"
#include "parser/parse_oper.h"
#include "partitioning/partdesc.h"
#include "pgstat.h"
#include "rewrite/rewriteManip.h"
#include "storage/lmgr.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "storage/sinvaladt.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/partcache.h"
#include "utils/pg_rusage.h"
#include "utils/regproc.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"

#include "catalog/aoblkdir.h"
#include "catalog/pg_constraint.h"
#include "catalog/oid_dispatch.h"
#include "catalog/pg_appendonly.h"
#include "cdb/cdbcat.h"
#include "cdb/cdbdisp_query.h"
#include "cdb/cdbdispatchresult.h"
#include "cdb/cdboidsync.h"
#include "cdb/cdbrelsize.h"
#include "cdb/cdbvars.h"
#include "libpq-fe.h"
#include "utils/faultinjector.h"

/* non-export function prototypes */
static void CheckPredicate(Expr *predicate);
static void ComputeIndexAttrs(IndexInfo *indexInfo,
				  Oid *typeOidP,
				  Oid *collationOidP,
				  Oid *classOidP,
				  int16 *colOptionP,
				  List *attList,
				  List *exclusionOpNames,
				  Oid relId,
				  const char *accessMethodName, Oid accessMethodId,
				  bool amcanorder,
				  bool isconstraint);
static char *ChooseIndexNameAddition(List *colnames);
static void RangeVarCallbackForReindexIndex(const RangeVar *relation,
											Oid relId, Oid oldRelId, void *arg);
static bool ReindexRelationConcurrently(Oid relationOid, int options);

static void ReindexPartitions(Oid relid, int options, bool concurrent, bool isTopLevel);
static void ReindexMultipleInternal(List *relids, int options, bool concurrent);
static void reindex_error_callback(void *args);
static void update_relispartition(Oid relationId, bool newval);

/*
 * callback argument type for RangeVarCallbackForReindexIndex()
 */
struct ReindexIndexCallbackState
{
	bool		concurrent;		/* flag from statement */
	Oid			locked_table_oid;	/* tracks previously locked table */
};


/*
 * Helper function, to check indcheckxmin for an index on all segments, and
 * set it on the master if it was set on any segment.
 *
 * If CREATE INDEX creates a "broken" HOT chain, the new index must not be
 * used by new queries, with an old snapshot, that would need to see the old
 * values. See src/backend/access/heap/README.HOT. This is enforced by
 * setting indcheckxmin in the pg_index row. In GPDB, we use the pg_index
 * row in the master for planning, but all the data is stored in the
 * segments, so indcheckxmin must be set in the master, if it's set in any
 * of the segments.
 */
static void
cdb_sync_indcheckxmin_with_segments(Oid indexRelationId)
{
	CdbPgResults cdb_pgresults = {NULL, 0};
	int			i;
	char		cmd[100];
	bool		indcheckxmin_set_in_any_segment;

	Assert(Gp_role == GP_ROLE_DISPATCH && !IsBootstrapProcessingMode());

	/*
	 * Query all the segments, for their indcheckxmin value for this index.
	 */
	snprintf(cmd, sizeof(cmd),
			 "select indcheckxmin from pg_catalog.pg_index where indexrelid = '%u'",
			 indexRelationId);

	CdbDispatchCommand(cmd, DF_WITH_SNAPSHOT, &cdb_pgresults);

	indcheckxmin_set_in_any_segment = false;
	for (i = 0; i < cdb_pgresults.numResults; i++)
	{
		char	   *val;

		if (PQresultStatus(cdb_pgresults.pg_results[i]) != PGRES_TUPLES_OK)
		{
			cdbdisp_clearCdbPgResults(&cdb_pgresults);
			elog(ERROR, "could not fetch indcheckxmin from segment");
		}

		if (PQntuples(cdb_pgresults.pg_results[i]) != 1 ||
			PQnfields(cdb_pgresults.pg_results[i]) != 1 ||
			PQgetisnull(cdb_pgresults.pg_results[i], 0, 0))
			elog(ERROR, "unexpected shape of result set for indcheckxmin query");

		val = PQgetvalue(cdb_pgresults.pg_results[i], 0, 0);
		if (val[0] == 't')
		{
			indcheckxmin_set_in_any_segment = true;
			break;
		}
		else if (val[0] != 'f')
			elog(ERROR, "invalid boolean value received from segment: %s", val);
	}

	cdbdisp_clearCdbPgResults(&cdb_pgresults);

	/*
	 * If indcheckxmin was set on any segment, also set it in the master.
	 */
	if (indcheckxmin_set_in_any_segment)
	{
		Relation	pg_index;
		HeapTuple	indexTuple;
		Form_pg_index indexForm;

		pg_index = heap_open(IndexRelationId, RowExclusiveLock);

		indexTuple = SearchSysCacheCopy1(INDEXRELID, ObjectIdGetDatum(indexRelationId));
		if (!HeapTupleIsValid(indexTuple))
			elog(ERROR, "cache lookup failed for index %u", indexRelationId);
		indexForm = (Form_pg_index) GETSTRUCT(indexTuple);

		if (!indexForm->indcheckxmin)
		{
			indexForm->indcheckxmin = true;
			CatalogTupleUpdate(pg_index, &indexTuple->t_self, indexTuple);
		}

		heap_freetuple(indexTuple);
		heap_close(pg_index, RowExclusiveLock);
	}
}

/*
 * callback arguments for reindex_error_callback()
 */
typedef struct ReindexErrorInfo
{
	char	   *relname;
	char	   *relnamespace;
	char		relkind;
} ReindexErrorInfo;

/*
 * CheckIndexCompatible
 *		Determine whether an existing index definition is compatible with a
 *		prospective index definition, such that the existing index storage
 *		could become the storage of the new index, avoiding a rebuild.
 *
 * 'heapRelation': the relation the index would apply to.
 * 'accessMethodName': name of the AM to use.
 * 'attributeList': a list of IndexElem specifying columns and expressions
 *		to index on.
 * 'exclusionOpNames': list of names of exclusion-constraint operators,
 *		or NIL if not an exclusion constraint.
 *
 * This is tailored to the needs of ALTER TABLE ALTER TYPE, which recreates
 * any indexes that depended on a changing column from their pg_get_indexdef
 * or pg_get_constraintdef definitions.  We omit some of the sanity checks of
 * DefineIndex.  We assume that the old and new indexes have the same number
 * of columns and that if one has an expression column or predicate, both do.
 * Errors arising from the attribute list still apply.
 *
 * Most column type changes that can skip a table rewrite do not invalidate
 * indexes.  We acknowledge this when all operator classes, collations and
 * exclusion operators match.  Though we could further permit intra-opfamily
 * changes for btree and hash indexes, that adds subtle complexity with no
 * concrete benefit for core types. Note, that INCLUDE columns aren't
 * checked by this function, for them it's enough that table rewrite is
 * skipped.
 *
 * When a comparison or exclusion operator has a polymorphic input type, the
 * actual input types must also match.  This defends against the possibility
 * that operators could vary behavior in response to get_fn_expr_argtype().
 * At present, this hazard is theoretical: check_exclusion_constraint() and
 * all core index access methods decline to set fn_expr for such calls.
 *
 * We do not yet implement a test to verify compatibility of expression
 * columns or predicates, so assume any such index is incompatible.
 */
bool
CheckIndexCompatible(Oid oldId,
					 const char *accessMethodName,
					 List *attributeList,
					 List *exclusionOpNames)
{
	bool		isconstraint;
	Oid		   *typeObjectId;
	Oid		   *collationObjectId;
	Oid		   *classObjectId;
	Oid			accessMethodId;
	Oid			relationId;
	HeapTuple	tuple;
	Form_pg_index indexForm;
	Form_pg_am	accessMethodForm;
	IndexAmRoutine *amRoutine;
	bool		amcanorder;
	int16	   *coloptions;
	IndexInfo  *indexInfo;
	int			numberOfAttributes;
	int			old_natts;
	bool		isnull;
	bool		ret = true;
	oidvector  *old_indclass;
	oidvector  *old_indcollation;
	Relation	irel;
	int			i;
	Datum		d;

	/* Caller should already have the relation locked in some way. */
	relationId = IndexGetRelation(oldId, false);

	/*
	 * We can pretend isconstraint = false unconditionally.  It only serves to
	 * decide the text of an error message that should never happen for us.
	 */
	isconstraint = false;

	numberOfAttributes = list_length(attributeList);
	Assert(numberOfAttributes > 0);
	Assert(numberOfAttributes <= INDEX_MAX_KEYS);

	/* look up the access method */
	tuple = SearchSysCache1(AMNAME, PointerGetDatum(accessMethodName));
	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("access method \"%s\" does not exist",
						accessMethodName)));
	accessMethodForm = (Form_pg_am) GETSTRUCT(tuple);
	accessMethodId = accessMethodForm->oid;
	amRoutine = GetIndexAmRoutine(accessMethodForm->amhandler);
	ReleaseSysCache(tuple);

	amcanorder = amRoutine->amcanorder;

	/*
	 * Compute the operator classes, collations, and exclusion operators for
	 * the new index, so we can test whether it's compatible with the existing
	 * one.  Note that ComputeIndexAttrs might fail here, but that's OK:
	 * DefineIndex would have called this function with the same arguments
	 * later on, and it would have failed then anyway.  Our attributeList
	 * contains only key attributes, thus we're filling ii_NumIndexAttrs and
	 * ii_NumIndexKeyAttrs with same value.
	 */
	indexInfo = makeNode(IndexInfo);
	indexInfo->ii_NumIndexAttrs = numberOfAttributes;
	indexInfo->ii_NumIndexKeyAttrs = numberOfAttributes;
	indexInfo->ii_Expressions = NIL;
	indexInfo->ii_ExpressionsState = NIL;
	indexInfo->ii_PredicateState = NULL;
	indexInfo->ii_ExclusionOps = NULL;
	indexInfo->ii_ExclusionProcs = NULL;
	indexInfo->ii_ExclusionStrats = NULL;
	indexInfo->ii_Am = accessMethodId;
	indexInfo->ii_AmCache = NULL;
	indexInfo->ii_Context = CurrentMemoryContext;
	typeObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
	collationObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
	classObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
	coloptions = (int16 *) palloc(numberOfAttributes * sizeof(int16));
	ComputeIndexAttrs(indexInfo,
					  typeObjectId, collationObjectId, classObjectId,
					  coloptions, attributeList,
					  exclusionOpNames, relationId,
					  accessMethodName, accessMethodId,
					  amcanorder, isconstraint);


	/* Get the soon-obsolete pg_index tuple. */
	tuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(oldId));
	if (!HeapTupleIsValid(tuple))
		elog(ERROR, "cache lookup failed for index %u", oldId);
	indexForm = (Form_pg_index) GETSTRUCT(tuple);

	/*
	 * We don't assess expressions or predicates; assume incompatibility.
	 * Also, if the index is invalid for any reason, treat it as incompatible.
	 */
	if (!(heap_attisnull(tuple, Anum_pg_index_indpred, NULL) &&
		  heap_attisnull(tuple, Anum_pg_index_indexprs, NULL) &&
		  indexForm->indisvalid))
	{
		ReleaseSysCache(tuple);
		return false;
	}

	/* Any change in operator class or collation breaks compatibility. */
	old_natts = indexForm->indnkeyatts;
	Assert(old_natts == numberOfAttributes);

	d = SysCacheGetAttr(INDEXRELID, tuple, Anum_pg_index_indcollation, &isnull);
	Assert(!isnull);
	old_indcollation = (oidvector *) DatumGetPointer(d);

	d = SysCacheGetAttr(INDEXRELID, tuple, Anum_pg_index_indclass, &isnull);
	Assert(!isnull);
	old_indclass = (oidvector *) DatumGetPointer(d);

	ret = (memcmp(old_indclass->values, classObjectId,
				  old_natts * sizeof(Oid)) == 0 &&
		   memcmp(old_indcollation->values, collationObjectId,
				  old_natts * sizeof(Oid)) == 0);

	ReleaseSysCache(tuple);

	if (!ret)
		return false;

	/* For polymorphic opcintype, column type changes break compatibility. */
	irel = index_open(oldId, AccessShareLock);	/* caller probably has a lock */
	for (i = 0; i < old_natts; i++)
	{
		if (IsPolymorphicType(get_opclass_input_type(classObjectId[i])) &&
			TupleDescAttr(irel->rd_att, i)->atttypid != typeObjectId[i])
		{
			ret = false;
			break;
		}
	}

	/* Any change in exclusion operator selections breaks compatibility. */
	if (ret && indexInfo->ii_ExclusionOps != NULL)
	{
		Oid		   *old_operators,
				   *old_procs;
		uint16	   *old_strats;

		RelationGetExclusionInfo(irel, &old_operators, &old_procs, &old_strats);
		ret = memcmp(old_operators, indexInfo->ii_ExclusionOps,
					 old_natts * sizeof(Oid)) == 0;

		/* Require an exact input type match for polymorphic operators. */
		if (ret)
		{
			for (i = 0; i < old_natts && ret; i++)
			{
				Oid			left,
							right;

				op_input_types(indexInfo->ii_ExclusionOps[i], &left, &right);
				if ((IsPolymorphicType(left) || IsPolymorphicType(right)) &&
					TupleDescAttr(irel->rd_att, i)->atttypid != typeObjectId[i])
				{
					ret = false;
					break;
				}
			}
		}
	}

	index_close(irel, NoLock);
	return ret;
}


/*
 * WaitForOlderSnapshots
 *
 * Wait for transactions that might have an older snapshot than the given xmin
 * limit, because it might not contain tuples deleted just before it has
 * been taken. Obtain a list of VXIDs of such transactions, and wait for them
 * individually. This is used when building an index concurrently.
 *
 * We can exclude any running transactions that have xmin > the xmin given;
 * their oldest snapshot must be newer than our xmin limit.
 * We can also exclude any transactions that have xmin = zero, since they
 * evidently have no live snapshot at all (and any one they might be in
 * process of taking is certainly newer than ours).  Transactions in other
 * DBs can be ignored too, since they'll never even be able to see the
 * index being worked on.
 *
 * We can also exclude autovacuum processes and processes running manual
 * lazy VACUUMs, because they won't be fazed by missing index entries
 * either.  (Manual ANALYZEs, however, can't be excluded because they
 * might be within transactions that are going to do arbitrary operations
 * later.)
 *
 * Also, GetCurrentVirtualXIDs never reports our own vxid, so we need not
 * check for that.
 *
 * If a process goes idle-in-transaction with xmin zero, we do not need to
 * wait for it anymore, per the above argument.  We do not have the
 * infrastructure right now to stop waiting if that happens, but we can at
 * least avoid the folly of waiting when it is idle at the time we would
 * begin to wait.  We do this by repeatedly rechecking the output of
 * GetCurrentVirtualXIDs.  If, during any iteration, a particular vxid
 * doesn't show up in the output, we know we can forget about it.
 */
static void
WaitForOlderSnapshots(TransactionId limitXmin, bool progress)
{
	int			n_old_snapshots;
	int			i;
	VirtualTransactionId *old_snapshots;

	old_snapshots = GetCurrentVirtualXIDs(limitXmin, true, false,
										  PROC_IS_AUTOVACUUM | PROC_IN_VACUUM,
										  &n_old_snapshots);
	if (progress)
		pgstat_progress_update_param(PROGRESS_WAITFOR_TOTAL, n_old_snapshots);

	for (i = 0; i < n_old_snapshots; i++)
	{
		if (!VirtualTransactionIdIsValid(old_snapshots[i]))
			continue;			/* found uninteresting in previous cycle */

		if (i > 0)
		{
			/* see if anything's changed ... */
			VirtualTransactionId *newer_snapshots;
			int			n_newer_snapshots;
			int			j;
			int			k;

			newer_snapshots = GetCurrentVirtualXIDs(limitXmin,
													true, false,
													PROC_IS_AUTOVACUUM | PROC_IN_VACUUM,
													&n_newer_snapshots);
			for (j = i; j < n_old_snapshots; j++)
			{
				if (!VirtualTransactionIdIsValid(old_snapshots[j]))
					continue;	/* found uninteresting in previous cycle */
				for (k = 0; k < n_newer_snapshots; k++)
				{
					if (VirtualTransactionIdEquals(old_snapshots[j],
												   newer_snapshots[k]))
						break;
				}
				if (k >= n_newer_snapshots) /* not there anymore */
					SetInvalidVirtualTransactionId(old_snapshots[j]);
			}
			pfree(newer_snapshots);
		}

		if (VirtualTransactionIdIsValid(old_snapshots[i]))
		{
			if (progress)
			{
				PGPROC	   *holder = BackendIdGetProc(old_snapshots[i].backendId);

				pgstat_progress_update_param(PROGRESS_WAITFOR_CURRENT_PID,
											 holder->pid);
			}
			VirtualXactLock(old_snapshots[i], true);
		}

		if (progress)
			pgstat_progress_update_param(PROGRESS_WAITFOR_DONE, i + 1);
	}
}


/*
 * DefineIndex
 *		Creates a new index.
 *
 * 'relationId': the OID of the heap relation on which the index is to be
 *		created
 * 'stmt': IndexStmt describing the properties of the new index.
 * 'indexRelationId': normally InvalidOid, but during bootstrap can be
 *		nonzero to specify a preselected OID for the index.
 * 'parentIndexId': the OID of the parent index; InvalidOid if not the child
 *		of a partitioned index.
 * 'parentConstraintId': the OID of the parent constraint; InvalidOid if not
 *		the child of a constraint (only used when recursing)
 * 'is_alter_table': this is due to an ALTER rather than a CREATE operation.
 * 'check_rights': check for CREATE rights in namespace and tablespace.  (This
 *		should be true except when ALTER is deleting/recreating an index.)
 * 'check_not_in_use': check for table not already in use in current session.
 *		This should be true unless caller is holding the table open, in which
 *		case the caller had better have checked it earlier.
 * 'skip_build': make the catalog entries but don't create the index files
 * 'quiet': suppress the NOTICE chatter ordinarily provided for constraints.
 *
 * GPDB:
 * 'is_new_table': is the parent relation new, guaranteed to still be empty?
 *
 * Returns the object address of the created index.
 */
ObjectAddress
DefineIndex(Oid relationId,
			IndexStmt *stmt,
			Oid indexRelationId,
			Oid parentIndexId,
			Oid parentConstraintId,
			bool is_alter_table,
			bool check_rights,
			bool check_not_in_use,
			bool skip_build,
			bool quiet,
			bool is_new_table)
{
	char	   *indexRelationName;
	char	   *accessMethodName;
	Oid		   *typeObjectId;
	Oid		   *collationObjectId;
	Oid		   *classObjectId;
	Oid			accessMethodId;
	Oid			namespaceId;
	Oid			tablespaceId;
	Oid			createdConstraintId = InvalidOid;
	List	   *indexColNames;
	List	   *allIndexParams;
	Relation	rel;
	HeapTuple	tuple;
	Form_pg_am	accessMethodForm;
	IndexAmRoutine *amRoutine;
	bool		amcanorder;
	amoptions_function amoptions;
	bool		partitioned;
	Datum		reloptions;
	int16	   *coloptions;
	IndexInfo  *indexInfo;
	bits16		flags;
	bits16		constr_flags;
	int			numberOfAttributes;
	int			numberOfKeyAttributes;
	TransactionId limitXmin;
	ObjectAddress address;
	LockRelId	heaprelid;
	LOCKTAG		heaplocktag;
	LOCKMODE	lockmode;
	Snapshot	snapshot;
	int			save_nestlevel = -1;
	bool		shouldDispatch;
	int			i;

	if (Gp_role == GP_ROLE_DISPATCH && !IsBootstrapProcessingMode())
		shouldDispatch = true;
	else
		shouldDispatch = false;

	if (parentIndexId)
	{
		/*
		 * If we're recursing for partitions, don't dispatch this command
		 * separately. We will dispatch the parent command.
		 */
		shouldDispatch = false;
	}

	/*
	 * Also don't dispatch this if it's part of an ALTER TABLE. We will dispatch
	 * the whole ALTER TABLE command later.
	 */
	if (is_alter_table)
		shouldDispatch = false;

	/*
	 * Some callers need us to run with an empty default_tablespace; this is a
	 * necessary hack to be able to reproduce catalog state accurately when
	 * recreating indexes after table-rewriting ALTER TABLE.
	 */
	if (stmt->reset_default_tblspc)
	{
		save_nestlevel = NewGUCNestLevel();
		(void) set_config_option("default_tablespace", "",
								 PGC_USERSET, PGC_S_SESSION,
								 GUC_ACTION_SAVE, true, 0, false);
	}

	/*
	 * Start progress report.  If we're building a partition, this was already
	 * done.
	 */
	if (!OidIsValid(parentIndexId))
	{
		pgstat_progress_start_command(PROGRESS_COMMAND_CREATE_INDEX,
									  relationId);
		pgstat_progress_update_param(PROGRESS_CREATEIDX_COMMAND,
									 stmt->concurrent ?
									 PROGRESS_CREATEIDX_COMMAND_CREATE_CONCURRENTLY :
									 PROGRESS_CREATEIDX_COMMAND_CREATE);
	}

	/*
	 * No index OID to report yet
	 */
	pgstat_progress_update_param(PROGRESS_CREATEIDX_INDEX_OID,
								 InvalidOid);

	/*
	 * count key attributes in index
	 */
	numberOfKeyAttributes = list_length(stmt->indexParams);

	/*
	 * Calculate the new list of index columns including both key columns and
	 * INCLUDE columns.  Later we can determine which of these are key
	 * columns, and which are just part of the INCLUDE list by checking the
	 * list position.  A list item in a position less than ii_NumIndexKeyAttrs
	 * is part of the key columns, and anything equal to and over is part of
	 * the INCLUDE columns.
	 */
	allIndexParams = list_concat(list_copy(stmt->indexParams),
								 list_copy(stmt->indexIncludingParams));
	numberOfAttributes = list_length(allIndexParams);

	if (numberOfAttributes <= 0)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
				 errmsg("must specify at least one column")));
	if (numberOfAttributes > INDEX_MAX_KEYS)
		ereport(ERROR,
				(errcode(ERRCODE_TOO_MANY_COLUMNS),
				 errmsg("cannot use more than %d columns in an index",
						INDEX_MAX_KEYS)));

	/*
	 * Only SELECT ... FOR UPDATE/SHARE are allowed while doing a standard
	 * index build; but for concurrent builds we allow INSERT/UPDATE/DELETE
	 * (but not VACUUM).
	 *
	 * NB: Caller is responsible for making sure that relationId refers to the
	 * relation on which the index should be built; except in bootstrap mode,
	 * this will typically require the caller to have already locked the
	 * relation.  To avoid lock upgrade hazards, that lock should be at least
	 * as strong as the one we take here.
	 *
	 * NB: If the lock strength here ever changes, code that is run by
	 * parallel workers under the control of certain particular ambuild
	 * functions will need to be updated, too.
	 */
	lockmode = stmt->concurrent ? ShareUpdateExclusiveLock : ShareLock;

	/*
	 * Appendoptimized tables need block directory relation for index
	 * access. Creating and maintaining block directory is expensive,
	 * because it needs to be kept up to date whenever new data is inserted
	 * in the table. We delay the block directory creation until it is
	 * really needed - the first index creation. Once created, all indexes
	 * share the same block directory. We need stronger lock
	 * (ShareRowExclusiveLock) that blocks index creation from another
	 * transaction (not to be confused with create index concurrently) as
	 * well as concurrent insert for appendoptimized tables, if the block
	 * directory needs to be created. If the block directory already exists,
	 * we can use the same lock as heap tables.
	 */
	rel = table_open(relationId, NoLock);
	if (RelationIsAppendOptimized(rel))
	{
		Oid blkdirrelid = InvalidOid;
		GetAppendOnlyEntryAuxOids(relationId, NULL, NULL, &blkdirrelid, NULL, NULL, NULL);

		if (!OidIsValid(blkdirrelid))
			lockmode = ShareRowExclusiveLock; /* Relation is AO, and has no block directory */
	}
	table_close(rel, NoLock);

	rel = table_open(relationId, lockmode);

	namespaceId = RelationGetNamespace(rel);

	/* Ensure that it makes sense to index this kind of relation */
	switch (rel->rd_rel->relkind)
	{
		case RELKIND_RELATION:
		case RELKIND_MATVIEW:
		case RELKIND_PARTITIONED_TABLE:
			/* OK */
			break;
		case RELKIND_FOREIGN_TABLE:

			/*
			 * Custom error message for FOREIGN TABLE since the term is close
			 * to a regular table and can confuse the user.
			 */
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("cannot create index on foreign table \"%s\"",
							RelationGetRelationName(rel))));
			break;
		default:
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("\"%s\" is not a table or materialized view",
							RelationGetRelationName(rel))));
			break;
	}

	/*
	 * Establish behavior for partitioned tables, and verify sanity of
	 * parameters.
	 *
	 * We do not build an actual index in this case; we only create a few
	 * catalog entries.  The actual indexes are built by recursing for each
	 * partition.
	 */
	partitioned = rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE;
	if (partitioned)
	{
		if (stmt->concurrent)
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("cannot create index on partitioned table \"%s\" concurrently",
							RelationGetRelationName(rel))));
		if (stmt->excludeOpNames)
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("cannot create exclusion constraints on partitioned table \"%s\"",
							RelationGetRelationName(rel))));
	}

	/*
	 * Don't try to CREATE INDEX on temp tables of other backends.
	 */
	if (RELATION_IS_OTHER_TEMP(rel))
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("cannot create indexes on temporary tables of other sessions")));

	/*
	 * Unless our caller vouches for having checked this already, insist that
	 * the table not be in use by our own session, either.  Otherwise we might
	 * fail to make entries in the new index (for instance, if an INSERT or
	 * UPDATE is in progress and has already made its list of target indexes).
	 */
	if (check_not_in_use)
		CheckTableNotInUse(rel, "CREATE INDEX");

	/*
	 * Verify we (still) have CREATE rights in the rel's namespace.
	 * (Presumably we did when the rel was created, but maybe not anymore.)
	 * Skip check if caller doesn't want it.  Also skip check if
	 * bootstrapping, since permissions machinery may not be working yet.
	 */
	if (check_rights && !IsBootstrapProcessingMode())
	{
		AclResult	aclresult;

		aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(),
										  ACL_CREATE);
		if (aclresult != ACLCHECK_OK)
			aclcheck_error(aclresult, OBJECT_SCHEMA,
						   get_namespace_name(namespaceId));
	}

	/*
	 * Select tablespace to use.  If not specified, use default tablespace
	 * (which may in turn default to database's default).
	 *
	 * Note: This code duplicates code in tablecmds.c
	 *
	 * MPP-8238 : inconsistent tablespaces between segments and master. In the
	 * QD, store the resolved tablespace name in the command, so that it's
	 * dispatched. In QE, skip the check for 'partitioned': because we got
	 * the value from the QD, it should be ok.
	 */
	if (stmt->tableSpace)
	{
		tablespaceId = get_tablespace_oid(stmt->tableSpace, false);
		if (partitioned && tablespaceId == MyDatabaseTableSpace &&
			Gp_role != GP_ROLE_EXECUTE)
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("cannot specify default tablespace for partitioned relations")));
	}
	else
	{
		tablespaceId = GetDefaultTablespace(rel->rd_rel->relpersistence,
											partitioned);
		/* note InvalidOid is OK in this case */

		/* Need the real tablespace id for dispatch */
		if (!OidIsValid(tablespaceId)) 
			tablespaceId = MyDatabaseTableSpace;
	}

	/* Check tablespace permissions */
	if (check_rights &&
		OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
	{
		AclResult	aclresult;

		aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(),
										   ACL_CREATE);
		if (aclresult != ACLCHECK_OK)
			aclcheck_error(aclresult, OBJECT_TABLESPACE,
						   get_tablespace_name(tablespaceId));
	}

	/*
	 * Force shared indexes into the pg_global tablespace.  This is a bit of a
	 * hack but seems simpler than marking them in the BKI commands.  On the
	 * other hand, if it's not shared, don't allow it to be placed there.
	 */
	if (rel->rd_rel->relisshared)
		tablespaceId = GLOBALTABLESPACE_OID;
	else if (tablespaceId == GLOBALTABLESPACE_OID)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("only shared relations can be placed in pg_global tablespace")));

	/*
	 * Choose the index column names.
	 */
	indexColNames = ChooseIndexColumnNames(allIndexParams);

	/*
	 * Select name for index if caller didn't specify
	 *
	 * In GPDB, we need to coordinate the index name between the QD and the
	 * QEs. In the QD, after creating the child index, we stash the chosen
	 * index name in the "oid assignments" list that's normally used to sync
	 * OIDs between QD and QEs. Here, in the QE, we fetch the stashed name
	 * from the list.
	 */
	indexRelationName = stmt->idxname;
	if (indexRelationName == NULL)
	{
		if (OidIsValid(parentIndexId) && Gp_role == GP_ROLE_EXECUTE)
			indexRelationName = GetPreassignedIndexNameForChildIndex(parentIndexId,
																	 relationId);
		else
		{
			indexRelationName = ChooseIndexName(RelationGetRelationName(rel),
											namespaceId,
											indexColNames,
											stmt->excludeOpNames,
											stmt->primary,
											stmt->isconstraint);
		}
	}

	/*
	 * look up the access method, verify it can handle the requested features
	 */
	accessMethodName = stmt->accessMethod;
	tuple = SearchSysCache1(AMNAME, PointerGetDatum(accessMethodName));
	if (!HeapTupleIsValid(tuple))
	{
		/*
		 * Hack to provide more-or-less-transparent updating of old RTREE
		 * indexes to GiST: if RTREE is requested and not found, use GIST.
		 */
		if (strcmp(accessMethodName, "rtree") == 0)
		{
			ereport(NOTICE,
					(errmsg("substituting access method \"gist\" for obsolete method \"rtree\"")));
			accessMethodName = "gist";
			tuple = SearchSysCache1(AMNAME, PointerGetDatum(accessMethodName));
		}

		if (!HeapTupleIsValid(tuple))
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_OBJECT),
					 errmsg("access method \"%s\" does not exist",
							accessMethodName)));
	}
	accessMethodForm = (Form_pg_am) GETSTRUCT(tuple);
	accessMethodId = accessMethodForm->oid;
	amRoutine = GetIndexAmRoutine(accessMethodForm->amhandler);

	pgstat_progress_update_param(PROGRESS_CREATEIDX_ACCESS_METHOD_OID,
								 accessMethodId);

	if (stmt->unique && !amRoutine->amcanunique)
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("access method \"%s\" does not support unique indexes",
						accessMethodName)));
	if (stmt->indexIncludingParams != NIL && !amRoutine->amcaninclude)
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("access method \"%s\" does not support included columns",
						accessMethodName)));
	if (numberOfAttributes > 1 && !amRoutine->amcanmulticol)
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("access method \"%s\" does not support multicolumn indexes",
						accessMethodName)));
	if (stmt->excludeOpNames && amRoutine->amgettuple == NULL)
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("access method \"%s\" does not support exclusion constraints",
						accessMethodName)));

    if  (stmt->unique && RelationIsAppendOptimized(rel))
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("append-only tables do not support unique indexes")));

	amcanorder = amRoutine->amcanorder;
	amoptions = amRoutine->amoptions;

	pfree(amRoutine);
	ReleaseSysCache(tuple);

	/*
	 * Validate predicate, if given
	 */
	if (stmt->whereClause)
		CheckPredicate((Expr *) stmt->whereClause);

	/*
	 * Parse AM-specific options, convert to text array form, validate.
	 */
	reloptions = transformRelOptions((Datum) 0, stmt->options,
									 NULL, NULL, false, false);

	(void) index_reloptions(amoptions, reloptions, true);

	/*
	 * Prepare arguments for index_create, primarily an IndexInfo structure.
	 * Note that ii_Predicate must be in implicit-AND format.
	 */
	indexInfo = makeNode(IndexInfo);
	indexInfo->ii_NumIndexAttrs = numberOfAttributes;
	indexInfo->ii_NumIndexKeyAttrs = numberOfKeyAttributes;
	indexInfo->ii_Expressions = NIL;	/* for now */
	indexInfo->ii_ExpressionsState = NIL;
	indexInfo->ii_Predicate = make_ands_implicit((Expr *) stmt->whereClause);
	indexInfo->ii_PredicateState = NULL;
	indexInfo->ii_ExclusionOps = NULL;
	indexInfo->ii_ExclusionProcs = NULL;
	indexInfo->ii_ExclusionStrats = NULL;
	indexInfo->ii_Unique = stmt->unique;
	/* In a concurrent build, mark it not-ready-for-inserts */
	indexInfo->ii_ReadyForInserts = !stmt->concurrent;
	indexInfo->ii_Concurrent = stmt->concurrent;
	indexInfo->ii_BrokenHotChain = false;
	indexInfo->ii_ParallelWorkers = 0;
	indexInfo->ii_Am = accessMethodId;
	indexInfo->ii_AmCache = NULL;
	indexInfo->ii_Context = CurrentMemoryContext;

	typeObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
	collationObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
	classObjectId = (Oid *) palloc(numberOfAttributes * sizeof(Oid));
	coloptions = (int16 *) palloc(numberOfAttributes * sizeof(int16));
	ComputeIndexAttrs(indexInfo,
					  typeObjectId, collationObjectId, classObjectId,
					  coloptions, allIndexParams,
					  stmt->excludeOpNames, relationId,
					  accessMethodName, accessMethodId,
					  amcanorder, stmt->isconstraint);

	/*
	 * Extra checks when creating a PRIMARY KEY index.
	 */
	if (stmt->primary)
		index_check_primary_key(rel, indexInfo, is_alter_table, stmt);

	/*
	 * Check that the index is compatible with the distribution policy.
	 *
	 * If the index is unique, the index columns must include all the
	 * distribution key columns. Otherwise we cannot enforce the uniqueness,
	 * because rows with duplicate keys might be stored in differenet segments,
	 * and we would miss it. Similarly, an exlusion constraint must include
	 * all all the distribution key columns.
	 *
	 * As a convenience, if it's a newly created table, we try to change the
	 * policy to allow the index to exist, instead of throwing an error. This
	 * allows the typical case of CREATE TABLE, without a DISTRIBUTED BY
	 * clause, followed by CREATE UNIQUE INDEX, to work. This is a bit weird
	 * if the user specified the distribution policy explicitly in the
	 * CREATE TABLE clause, but we have no way of knowing whether it was
	 * specified explicitly or not.
	 */
	if (rel->rd_cdbpolicy && (stmt->primary || stmt->unique || stmt->excludeOpNames))
	{
		index_check_policy_compatible_context ctx;

		/* Don't allow indexes on system attributes. */
		for (int i = 0; i < indexInfo->ii_NumIndexKeyAttrs; i++)
		{
			if (indexInfo->ii_IndexAttrNumbers[i] < 0)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
						 errmsg("cannot create constraint or unique index on system column")));
		}
		memset(&ctx, 0, sizeof(ctx));
		ctx.for_alter_dist_policy = false;
		ctx.is_constraint = stmt->isconstraint;
		ctx.is_unique = stmt->unique;
		ctx.is_primarykey = stmt->primary;
		ctx.constraint_name = indexRelationName;
		(void) index_check_policy_compatible(rel->rd_cdbpolicy,
											 RelationGetDescr(rel),
											 indexInfo->ii_IndexAttrNumbers,
											 classObjectId,
											 indexInfo->ii_ExclusionOps,
											 indexInfo->ii_NumIndexKeyAttrs,
											 true, /* report_error */
											 &ctx);
	}

	/*
	 * If this table is partitioned and we're creating a unique index or a
	 * primary key, make sure that the indexed columns are part of the
	 * partition key.  Otherwise it would be possible to violate uniqueness by
	 * putting values that ought to be unique in different partitions.
	 *
	 * We could lift this limitation if we had global indexes, but those have
	 * their own problems, so this is a useful feature combination.
	 */
	if (partitioned && (stmt->unique || stmt->primary))
	{
		PartitionKey key = rel->rd_partkey;
		int			i;

		/*
		 * A partitioned table can have unique indexes, as long as all the
		 * columns in the partition key appear in the unique key.  A
		 * partition-local index can enforce global uniqueness iff the PK
		 * value completely determines the partition that a row is in.
		 *
		 * Thus, verify that all the columns in the partition key appear in
		 * the unique key definition.
		 */
		for (i = 0; i < key->partnatts; i++)
		{
			bool		found = false;
			int			j;
			const char *constraint_type;

			if (stmt->primary)
				constraint_type = "PRIMARY KEY";
			else if (stmt->unique)
				constraint_type = "UNIQUE";
			else if (stmt->excludeOpNames != NIL)
				constraint_type = "EXCLUDE";
			else
			{
				elog(ERROR, "unknown constraint type");
				constraint_type = NULL; /* keep compiler quiet */
			}

			/*
			 * It may be possible to support UNIQUE constraints when partition
			 * keys are expressions, but is it worth it?  Give up for now.
			 */
			if (key->partattrs[i] == 0)
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("unsupported %s constraint with partition key definition",
								constraint_type),
						 errdetail("%s constraints cannot be used when partition keys include expressions.",
								   constraint_type)));

			for (j = 0; j < indexInfo->ii_NumIndexKeyAttrs; j++)
			{
				if (key->partattrs[i] == indexInfo->ii_IndexAttrNumbers[j])
				{
					found = true;
					break;
				}
			}
			if (!found)
			{
				Form_pg_attribute att;

				att = TupleDescAttr(RelationGetDescr(rel), key->partattrs[i] - 1);
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("insufficient columns in %s constraint definition",
								constraint_type),
						 errdetail("%s constraint on table \"%s\" lacks column \"%s\" which is part of the partition key.",
								   constraint_type, RelationGetRelationName(rel),
								   NameStr(att->attname))));
			}
		}
	}

	if (Gp_role == GP_ROLE_EXECUTE && stmt)
		quiet = true;

	/*
	 * We disallow indexes on system columns.  They would not necessarily get
	 * updated correctly, and they don't seem useful anyway.
	 */
	for (i = 0; i < indexInfo->ii_NumIndexAttrs; i++)
	{
		AttrNumber	attno = indexInfo->ii_IndexAttrNumbers[i];

		if (attno < 0)
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("index creation on system columns is not supported")));
	}

	/*
	 * Also check for system columns used in expressions or predicates.
	 */
	if (indexInfo->ii_Expressions || indexInfo->ii_Predicate)
	{
		Bitmapset  *indexattrs = NULL;

		pull_varattnos((Node *) indexInfo->ii_Expressions, 1, &indexattrs);
		pull_varattnos((Node *) indexInfo->ii_Predicate, 1, &indexattrs);

		for (i = FirstLowInvalidHeapAttributeNumber + 1; i < 0; i++)
		{
			if (bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
							  indexattrs))
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("index creation on system columns is not supported")));
		}
	}

	/*
	 * Report index creation if appropriate (delay this till after most of the
	 * error checks)
	 */
	if (stmt->isconstraint && !quiet && Gp_role != GP_ROLE_EXECUTE)
	{
		const char *constraint_type;

		if (stmt->primary)
			constraint_type = "PRIMARY KEY";
		else if (stmt->unique)
			constraint_type = "UNIQUE";
		else if (stmt->excludeOpNames != NIL)
			constraint_type = "EXCLUDE";
		else
		{
			elog(ERROR, "unknown constraint type");
			constraint_type = NULL; /* keep compiler quiet */
		}

		ereport(DEBUG1,
				(errmsg("%s %s will create implicit index \"%s\" for table \"%s\"",
						is_alter_table ? "ALTER TABLE / ADD" : "CREATE TABLE /",
						constraint_type,
						indexRelationName, RelationGetRelationName(rel))));
	}

	if (shouldDispatch)
	{
		cdb_sync_oid_to_segments();

		/*
		 * We defer the dispatch of the utility command until after
		 * index_create(), because that call will *wait*
		 * for any other transactions touching this new relation,
		 * which can cause a non-local deadlock if we've already
		 * dispatched
		 */
	}

	/*
	 * A valid stmt->oldNode implies that we already have a built form of the
	 * index.  The caller should also decline any index build.
	 */
	Assert(!OidIsValid(stmt->oldNode) || (skip_build && !stmt->concurrent));

	/*
	 * Create block directory if this is an appendoptimized
	 * relation
	 */
	AlterTableCreateAoBlkdirTable(RelationGetRelid(rel));

	/*
	 * Make the catalog entries for the index, including constraints. This
	 * step also actually builds the index, except if caller requested not to
	 * or in concurrent mode, in which case it'll be done later, or doing a
	 * partitioned index (because those don't have storage).
	 */
	flags = constr_flags = 0;
	if (stmt->isconstraint)
		flags |= INDEX_CREATE_ADD_CONSTRAINT;
	if (skip_build || stmt->concurrent || partitioned)
		flags |= INDEX_CREATE_SKIP_BUILD;
	if (stmt->if_not_exists)
		flags |= INDEX_CREATE_IF_NOT_EXISTS;
	if (stmt->concurrent)
		flags |= INDEX_CREATE_CONCURRENT;
	if (partitioned)
		flags |= INDEX_CREATE_PARTITIONED;
	if (stmt->primary)
		flags |= INDEX_CREATE_IS_PRIMARY;

	/*
	 * If the table is partitioned, and recursion was declined but partitions
	 * exist, mark the index as invalid.
	 */
	if (partitioned && stmt->relation && !stmt->relation->inh)
	{
		PartitionDesc pd = RelationGetPartitionDesc(rel);

		if (pd->nparts != 0)
			flags |= INDEX_CREATE_INVALID;
	}

	if (stmt->deferrable)
		constr_flags |= INDEX_CONSTR_CREATE_DEFERRABLE;
	if (stmt->initdeferred)
		constr_flags |= INDEX_CONSTR_CREATE_INIT_DEFERRED;

	indexRelationId =
		index_create(rel, indexRelationName, indexRelationId, parentIndexId,
					 parentConstraintId,
					 stmt->oldNode, indexInfo, indexColNames,
					 accessMethodId, tablespaceId,
					 collationObjectId, classObjectId,
					 coloptions, reloptions,
					 flags, constr_flags,
					 allowSystemTableMods, !check_rights,
					 &createdConstraintId);

	ObjectAddressSet(address, RelationRelationId, indexRelationId);

	/*
	 * Revert to original default_tablespace.  Must do this before any return
	 * from this function, but after index_create, so this is a good time.
	 */
	if (save_nestlevel >= 0)
		AtEOXact_GUC(true, save_nestlevel);

	if (!OidIsValid(indexRelationId))
	{
		table_close(rel, NoLock);

		/* If this is the top-level index, we're done */
		if (!OidIsValid(parentIndexId))
			pgstat_progress_end_command();

		return address;
	}

	/*
	 * In the QD, remember the chosen index name and stash it with the
	 * chosen OIDs, so that it's dispatched to the QE later.
	 */
	if (OidIsValid(parentIndexId) && Gp_role == GP_ROLE_DISPATCH)
	{
		RememberPreassignedIndexNameForChildIndex(parentIndexId,
												  relationId,
												  indexRelationName);
	}

	/* Add any requested comment */
	if (stmt->idxcomment != NULL)
		CreateComments(indexRelationId, RelationRelationId, 0,
					   stmt->idxcomment);

	if (partitioned)
	{
		/*
		 * Unless caller specified to skip this step (via ONLY), process each
		 * partition to make sure they all contain a corresponding index.
		 *
		 * If we're called internally (no stmt->relation), recurse always.
		 */
		if (!stmt->relation || stmt->relation->inh)
		{
			PartitionDesc partdesc = RelationGetPartitionDesc(rel);
			int			nparts = partdesc->nparts;
			Oid		   *part_oids = palloc(sizeof(Oid) * nparts);
			bool		invalidate_parent = false;
			TupleDesc	parentDesc;
			Oid		   *opfamOids;

			pgstat_progress_update_param(PROGRESS_CREATEIDX_PARTITIONS_TOTAL,
										 nparts);

			memcpy(part_oids, partdesc->oids, sizeof(Oid) * nparts);

			parentDesc = RelationGetDescr(rel);
			opfamOids = palloc(sizeof(Oid) * numberOfKeyAttributes);
			for (i = 0; i < numberOfKeyAttributes; i++)
				opfamOids[i] = get_opclass_family(classObjectId[i]);

			/*
			 * For each partition, scan all existing indexes; if one matches
			 * our index definition and is not already attached to some other
			 * parent index, attach it to the one we just created.
			 *
			 * If none matches, build a new index by calling ourselves
			 * recursively with the same options (except for the index name).
			 */
			for (i = 0; i < nparts; i++)
			{
				Oid			childRelid = part_oids[i];
				Relation	childrel;
				List	   *childidxs;
				ListCell   *cell;
				AttrNumber *attmap;
				bool		found = false;
				int			maplen;

				childrel = table_open(childRelid, lockmode);

				/*
				 * Don't try to create indexes on foreign tables, though. Skip
				 * those if a regular index, or fail if trying to create a
				 * constraint index.
				 */
				if (childrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
				{
					if (stmt->unique || stmt->primary)
						ereport(ERROR,
								(errcode(ERRCODE_WRONG_OBJECT_TYPE),
								 errmsg("cannot create unique index on partitioned table \"%s\"",
										RelationGetRelationName(rel)),
								 errdetail("Table \"%s\" contains partitions that are foreign tables.",
										   RelationGetRelationName(rel))));

					table_close(childrel, lockmode);
					continue;
				}

				childidxs = RelationGetIndexList(childrel);
				attmap =
					convert_tuples_by_name_map(RelationGetDescr(childrel),
											   parentDesc,
											   gettext_noop("could not convert row type"));
				maplen = parentDesc->natts;

				foreach(cell, childidxs)
				{
					Oid			cldidxid = lfirst_oid(cell);
					Relation	cldidx;
					IndexInfo  *cldIdxInfo;

					/* this index is already partition of another one */
					if (has_superclass(cldidxid))
						continue;

					cldidx = index_open(cldidxid, lockmode);
					cldIdxInfo = BuildIndexInfo(cldidx);
					if (CompareIndexInfo(cldIdxInfo, indexInfo,
										 cldidx->rd_indcollation,
										 collationObjectId,
										 cldidx->rd_opfamily,
										 opfamOids,
										 attmap, maplen))
					{
						Oid			cldConstrOid = InvalidOid;

						/*
						 * Found a match.
						 *
						 * If this index is being created in the parent
						 * because of a constraint, then the child needs to
						 * have a constraint also, so look for one.  If there
						 * is no such constraint, this index is no good, so
						 * keep looking.
						 */
						if (createdConstraintId != InvalidOid)
						{
							cldConstrOid =
								get_relation_idx_constraint_oid(childRelid,
																cldidxid);
							if (cldConstrOid == InvalidOid)
							{
								index_close(cldidx, lockmode);
								continue;
							}
						}

						/* Attach index to parent and we're done. */
						IndexSetParentIndex(cldidx, indexRelationId);
						if (createdConstraintId != InvalidOid)
							ConstraintSetParentConstraint(cldConstrOid,
														  createdConstraintId,
														  childRelid);

						if (!cldidx->rd_index->indisvalid)
							invalidate_parent = true;

						found = true;
						/* keep lock till commit */
						index_close(cldidx, NoLock);
						break;
					}

					index_close(cldidx, lockmode);
				}

				list_free(childidxs);
				table_close(childrel, NoLock);

				/*
				 * If no matching index was found, create our own.
				 */
				if (!found)
				{
					IndexStmt  *childStmt = copyObject(stmt);
					bool		found_whole_row;
					ListCell   *lc;

					/*
					 * We can't use the same index name for the child index,
					 * so clear idxname to let the recursive invocation choose
					 * a new name.  Likewise, the existing target relation
					 * field is wrong, and if indexOid or oldNode are set,
					 * they mustn't be applied to the child either.
					 */
					childStmt->idxname = NULL;
					childStmt->relation = NULL;
					childStmt->indexOid = InvalidOid;
					childStmt->oldNode = InvalidOid;

					/*
					 * Adjust any Vars (both in expressions and in the index's
					 * WHERE clause) to match the partition's column numbering
					 * in case it's different from the parent's.
					 */
					foreach(lc, childStmt->indexParams)
					{
						IndexElem  *ielem = lfirst(lc);

						/*
						 * If the index parameter is an expression, we must
						 * translate it to contain child Vars.
						 */
						if (ielem->expr)
						{
							ielem->expr =
								map_variable_attnos((Node *) ielem->expr,
													1, 0, attmap, maplen,
													InvalidOid,
													&found_whole_row);
							if (found_whole_row)
								elog(ERROR, "cannot convert whole-row table reference");
						}
					}
					childStmt->whereClause =
						map_variable_attnos(stmt->whereClause, 1, 0,
											attmap, maplen,
											InvalidOid, &found_whole_row);
					if (found_whole_row)
						elog(ERROR, "cannot convert whole-row table reference");

					DefineIndex(childRelid, childStmt,
								InvalidOid, /* no predefined OID */
								indexRelationId,	/* this is our child */
								createdConstraintId,
								is_alter_table, check_rights, check_not_in_use,
								skip_build, quiet, is_new_table);
				}

				pgstat_progress_update_param(PROGRESS_CREATEIDX_PARTITIONS_DONE,
											 i + 1);
				pfree(attmap);
			}

			/*
			 * The pg_index row we inserted for this index was marked
			 * indisvalid=true.  But if we attached an existing index that is
			 * invalid, this is incorrect, so update our row to invalid too.
			 */
			if (invalidate_parent)
			{
				Relation	pg_index = table_open(IndexRelationId, RowExclusiveLock);
				HeapTuple	tup,
							newtup;

				tup = SearchSysCache1(INDEXRELID,
									  ObjectIdGetDatum(indexRelationId));
				if (!HeapTupleIsValid(tup))
					elog(ERROR, "cache lookup failed for index %u",
						 indexRelationId);
				newtup = heap_copytuple(tup);
				((Form_pg_index) GETSTRUCT(newtup))->indisvalid = false;
				CatalogTupleUpdate(pg_index, &tup->t_self, newtup);
				ReleaseSysCache(tup);
				table_close(pg_index, RowExclusiveLock);
				heap_freetuple(newtup);
			}
		}

		stmt->idxname = indexRelationName;
		if (shouldDispatch)
		{
			/* make sure the QE uses the same index name that we chose */
			stmt->oldNode = InvalidOid;
			Assert(stmt->relation != NULL);

			stmt->tableSpace = get_tablespace_name(tablespaceId);

			CdbDispatchUtilityStatement((Node *) stmt,
										DF_CANCEL_ON_ERROR |
										DF_WITH_SNAPSHOT |
										DF_NEED_TWO_PHASE,
										GetAssignedOidsForDispatch(),
										NULL);
		}

		/*
		 * Indexes on partitioned tables are not themselves built, so we're
		 * done here.
		 */
		table_close(rel, NoLock);
		if (!OidIsValid(parentIndexId))
			pgstat_progress_end_command();
		return address;
	}

	stmt->idxname = indexRelationName;
	if (shouldDispatch)
	{
		/* make sure the QE uses the same index name that we chose */
		stmt->oldNode = InvalidOid;
		Assert(stmt->relation != NULL);
		CdbDispatchUtilityStatement((Node *) stmt,
									DF_CANCEL_ON_ERROR |
									DF_WITH_SNAPSHOT |
									DF_NEED_TWO_PHASE,
									GetAssignedOidsForDispatch(),
									NULL);

		/* Set indcheckxmin in the master, if it was set on any segment */
		if (!indexInfo->ii_BrokenHotChain)
			cdb_sync_indcheckxmin_with_segments(indexRelationId);
	}

	if (!stmt->concurrent)
	{
		/* Close the heap and we're done, in the non-concurrent case */
		table_close(rel, NoLock);

		/* If this is the top-level index, we're done. */
		if (!OidIsValid(parentIndexId))
			pgstat_progress_end_command();

		return address;
	}

	/*
	 * FIXME: concurrent index build needs additional work in Greenplum.  The
	 * feature is disabled in Greenplum until this work is done.  In upstream,
	 * concurrent index build is accomplished in three steps.  Each step is
	 * performed in its own transaction.  In GPDB, each step must be performed
	 * in its own distributed transaction.  Today, we only support dispatching
	 * one IndexStmt.  QEs cannot distinguish the steps within a concurrent
	 * index build.  May be, augment IndexStmt with a variable indicating which
	 * step of concurrent index build a QE should perform?
	 */

	/* save lockrelid and locktag for below, then close rel */
	heaprelid = rel->rd_lockInfo.lockRelId;
	SET_LOCKTAG_RELATION(heaplocktag, heaprelid.dbId, heaprelid.relId);
	table_close(rel, NoLock);

	/*
	 * For a concurrent build, it's important to make the catalog entries
	 * visible to other transactions before we start to build the index. That
	 * will prevent them from making incompatible HOT updates.  The new index
	 * will be marked not indisready and not indisvalid, so that no one else
	 * tries to either insert into it or use it for queries.
	 *
	 * We must commit our current transaction so that the index becomes
	 * visible; then start another.  Note that all the data structures we just
	 * built are lost in the commit.  The only data we keep past here are the
	 * relation IDs.
	 *
	 * Before committing, get a session-level lock on the table, to ensure
	 * that neither it nor the index can be dropped before we finish. This
	 * cannot block, even if someone else is waiting for access, because we
	 * already have the same lock within our transaction.
	 *
	 * Note: we don't currently bother with a session lock on the index,
	 * because there are no operations that could change its state while we
	 * hold lock on the parent table.  This might need to change later.
	 */
	LockRelationIdForSession(&heaprelid, ShareUpdateExclusiveLock);

	PopActiveSnapshot();
	CommitTransactionCommand();

	StartTransactionCommand();

	/*
	 * The index is now visible, so we can report the OID.
	 */
	pgstat_progress_update_param(PROGRESS_CREATEIDX_INDEX_OID,
								 indexRelationId);

	/*
	 * Phase 2 of concurrent index build (see comments for validate_index()
	 * for an overview of how this works)
	 *
	 * Now we must wait until no running transaction could have the table open
	 * with the old list of indexes.  Use ShareLock to consider running
	 * transactions that hold locks that permit writing to the table.  Note we
	 * do not need to worry about xacts that open the table for writing after
	 * this point; they will see the new index when they open it.
	 *
	 * Note: the reason we use actual lock acquisition here, rather than just
	 * checking the ProcArray and sleeping, is that deadlock is possible if
	 * one of the transactions in question is blocked trying to acquire an
	 * exclusive lock on our table.  The lock code will detect deadlock and
	 * error out properly.
	 */
	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
								 PROGRESS_CREATEIDX_PHASE_WAIT_1);
	WaitForLockers(heaplocktag, ShareLock, true);

	/*
	 * At this moment we are sure that there are no transactions with the
	 * table open for write that don't have this new index in their list of
	 * indexes.  We have waited out all the existing transactions and any new
	 * transaction will have the new index in its list, but the index is still
	 * marked as "not-ready-for-inserts".  The index is consulted while
	 * deciding HOT-safety though.  This arrangement ensures that no new HOT
	 * chains can be created where the new tuple and the old tuple in the
	 * chain have different index keys.
	 *
	 * We now take a new snapshot, and build the index using all tuples that
	 * are visible in this snapshot.  We can be sure that any HOT updates to
	 * these tuples will be compatible with the index, since any updates made
	 * by transactions that didn't know about the index are now committed or
	 * rolled back.  Thus, each visible tuple is either the end of its
	 * HOT-chain or the extension of the chain is HOT-safe for this index.
	 */

	/* Set ActiveSnapshot since functions in the indexes may need it */
	PushActiveSnapshot(GetTransactionSnapshot());

	/* Perform concurrent build of index */
	index_concurrently_build(relationId, indexRelationId);

	/* we can do away with our snapshot */
	PopActiveSnapshot();

	/*
	 * Commit this transaction to make the indisready update visible.
	 */
	CommitTransactionCommand();
	StartTransactionCommand();

	/*
	 * Phase 3 of concurrent index build
	 *
	 * We once again wait until no transaction can have the table open with
	 * the index marked as read-only for updates.
	 */
	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
								 PROGRESS_CREATEIDX_PHASE_WAIT_2);
	WaitForLockers(heaplocktag, ShareLock, true);

	/*
	 * Now take the "reference snapshot" that will be used by validate_index()
	 * to filter candidate tuples.  Beware!  There might still be snapshots in
	 * use that treat some transaction as in-progress that our reference
	 * snapshot treats as committed.  If such a recently-committed transaction
	 * deleted tuples in the table, we will not include them in the index; yet
	 * those transactions which see the deleting one as still-in-progress will
	 * expect such tuples to be there once we mark the index as valid.
	 *
	 * We solve this by waiting for all endangered transactions to exit before
	 * we mark the index as valid.
	 *
	 * We also set ActiveSnapshot to this snap, since functions in indexes may
	 * need a snapshot.
	 */
	snapshot = RegisterSnapshot(GetTransactionSnapshot());
	PushActiveSnapshot(snapshot);

	/*
	 * Scan the index and the heap, insert any missing index entries.
	 */
	validate_index(relationId, indexRelationId, snapshot);

	/*
	 * Drop the reference snapshot.  We must do this before waiting out other
	 * snapshot holders, else we will deadlock against other processes also
	 * doing CREATE INDEX CONCURRENTLY, which would see our snapshot as one
	 * they must wait for.  But first, save the snapshot's xmin to use as
	 * limitXmin for GetCurrentVirtualXIDs().
	 */
	limitXmin = snapshot->xmin;

	PopActiveSnapshot();
	UnregisterSnapshot(snapshot);

	/*
	 * The snapshot subsystem could still contain registered snapshots that
	 * are holding back our process's advertised xmin; in particular, if
	 * default_transaction_isolation = serializable, there is a transaction
	 * snapshot that is still active.  The CatalogSnapshot is likewise a
	 * hazard.  To ensure no deadlocks, we must commit and start yet another
	 * transaction, and do our wait before any snapshot has been taken in it.
	 */
	CommitTransactionCommand();
	StartTransactionCommand();

	/* We should now definitely not be advertising any xmin. */
	Assert(MyPgXact->xmin == InvalidTransactionId);

	/*
	 * The index is now valid in the sense that it contains all currently
	 * interesting tuples.  But since it might not contain tuples deleted just
	 * before the reference snap was taken, we have to wait out any
	 * transactions that might have older snapshots.
	 */
	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
								 PROGRESS_CREATEIDX_PHASE_WAIT_3);
	WaitForOlderSnapshots(limitXmin, true);

	/*
	 * Index can now be marked valid -- update its pg_index entry
	 */
	index_set_state_flags(indexRelationId, INDEX_CREATE_SET_VALID);

	/*
	 * The pg_index update will cause backends (including this one) to update
	 * relcache entries for the index itself, but we should also send a
	 * relcache inval on the parent table to force replanning of cached plans.
	 * Otherwise existing sessions might fail to use the new index where it
	 * would be useful.  (Note that our earlier commits did not create reasons
	 * to replan; so relcache flush on the index itself was sufficient.)
	 */
	CacheInvalidateRelcacheByRelid(heaprelid.relId);

	/*
	 * Last thing to do is release the session-level lock on the parent table.
	 */
	UnlockRelationIdForSession(&heaprelid, ShareUpdateExclusiveLock);

	pgstat_progress_end_command();

	return address;
}


/*
 * CheckMutability
 *		Test whether given expression is mutable
 */
static bool
CheckMutability(Expr *expr)
{
	/*
	 * First run the expression through the planner.  This has a couple of
	 * important consequences.  First, function default arguments will get
	 * inserted, which may affect volatility (consider "default now()").
	 * Second, inline-able functions will get inlined, which may allow us to
	 * conclude that the function is really less volatile than it's marked. As
	 * an example, polymorphic functions must be marked with the most volatile
	 * behavior that they have for any input type, but once we inline the
	 * function we may be able to conclude that it's not so volatile for the
	 * particular input type we're dealing with.
	 *
	 * We assume here that expression_planner() won't scribble on its input.
	 */
	expr = expression_planner(expr);

	/* Now we can search for non-immutable functions */
	return contain_mutable_functions((Node *) expr);
}


/*
 * CheckPredicate
 *		Checks that the given partial-index predicate is valid.
 *
 * This used to also constrain the form of the predicate to forms that
 * indxpath.c could do something with.  However, that seems overly
 * restrictive.  One useful application of partial indexes is to apply
 * a UNIQUE constraint across a subset of a table, and in that scenario
 * any evaluable predicate will work.  So accept any predicate here
 * (except ones requiring a plan), and let indxpath.c fend for itself.
 */
static void
CheckPredicate(Expr *predicate)
{
	/*
	 * transformExpr() should have already rejected subqueries, aggregates,
	 * and window functions, based on the EXPR_KIND_ for a predicate.
	 */

	/*
	 * A predicate using mutable functions is probably wrong, for the same
	 * reasons that we don't allow an index expression to use one.
	 */
	if (CheckMutability(predicate))
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
				 errmsg("functions in index predicate must be marked IMMUTABLE")));
}

/*
 * Compute per-index-column information, including indexed column numbers
 * or index expressions, opclasses, and indoptions. Note, all output vectors
 * should be allocated for all columns, including "including" ones.
 */
static void
ComputeIndexAttrs(IndexInfo *indexInfo,
				  Oid *typeOidP,
				  Oid *collationOidP,
				  Oid *classOidP,
				  int16 *colOptionP,
				  List *attList,	/* list of IndexElem's */
				  List *exclusionOpNames,
				  Oid relId,
				  const char *accessMethodName,
				  Oid accessMethodId,
				  bool amcanorder,
				  bool isconstraint)
{
	ListCell   *nextExclOp;
	ListCell   *lc;
	int			attn;
	int			nkeycols = indexInfo->ii_NumIndexKeyAttrs;

	/* Allocate space for exclusion operator info, if needed */
	if (exclusionOpNames)
	{
		Assert(list_length(exclusionOpNames) == nkeycols);
		indexInfo->ii_ExclusionOps = (Oid *) palloc(sizeof(Oid) * nkeycols);
		indexInfo->ii_ExclusionProcs = (Oid *) palloc(sizeof(Oid) * nkeycols);
		indexInfo->ii_ExclusionStrats = (uint16 *) palloc(sizeof(uint16) * nkeycols);
		nextExclOp = list_head(exclusionOpNames);
	}
	else
		nextExclOp = NULL;

	/*
	 * process attributeList
	 */
	attn = 0;
	foreach(lc, attList)
	{
		IndexElem  *attribute = (IndexElem *) lfirst(lc);
		Oid			atttype;
		Oid			attcollation;

		/*
		 * Process the column-or-expression to be indexed.
		 */
		if (attribute->name != NULL)
		{
			/* Simple index attribute */
			HeapTuple	atttuple;
			Form_pg_attribute attform;

			Assert(attribute->expr == NULL);
			atttuple = SearchSysCacheAttName(relId, attribute->name);
			if (!HeapTupleIsValid(atttuple))
			{
				/* difference in error message spellings is historical */
				if (isconstraint)
					ereport(ERROR,
							(errcode(ERRCODE_UNDEFINED_COLUMN),
							 errmsg("column \"%s\" named in key does not exist",
									attribute->name)));
				else
					ereport(ERROR,
							(errcode(ERRCODE_UNDEFINED_COLUMN),
							 errmsg("column \"%s\" does not exist",
									attribute->name)));
			}
			attform = (Form_pg_attribute) GETSTRUCT(atttuple);
			indexInfo->ii_IndexAttrNumbers[attn] = attform->attnum;
			atttype = attform->atttypid;
			attcollation = attform->attcollation;
			ReleaseSysCache(atttuple);
		}
		else
		{
			/* Index expression */
			Node	   *expr = attribute->expr;

			Assert(expr != NULL);

			if (attn >= nkeycols)
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("expressions are not supported in included columns")));
			atttype = exprType(expr);
			attcollation = exprCollation(expr);

			/*
			 * transformExpr() should have already rejected subqueries,
			 * aggregates, and window functions, based on the EXPR_KIND_
			 * for an index expression.
			 */

			/*
			 * Strip any top-level COLLATE clause.  This ensures that we treat
			 * "x COLLATE y" and "(x COLLATE y)" alike.
			 */
			while (IsA(expr, CollateExpr))
				expr = (Node *) ((CollateExpr *) expr)->arg;

			if (IsA(expr, Var) &&
				((Var *) expr)->varattno != InvalidAttrNumber)
			{
				/*
				 * User wrote "(column)" or "(column COLLATE something)".
				 * Treat it like simple attribute anyway.
				 */
				indexInfo->ii_IndexAttrNumbers[attn] = ((Var *) expr)->varattno;
			}
			else
			{
				indexInfo->ii_IndexAttrNumbers[attn] = 0;	/* marks expression */
				indexInfo->ii_Expressions = lappend(indexInfo->ii_Expressions,
													expr);

				/*
				 * transformExpr() should have already rejected subqueries,
				 * aggregates, and window functions, based on the EXPR_KIND_
				 * for an index expression.
				 */

				/*
				 * An expression using mutable functions is probably wrong,
				 * since if you aren't going to get the same result for the
				 * same data every time, it's not clear what the index entries
				 * mean at all.
				 */
				if (CheckMutability((Expr *) expr))
					ereport(ERROR,
							(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
							 errmsg("functions in index expression must be marked IMMUTABLE")));
			}
		}

		typeOidP[attn] = atttype;

		/*
		 * Included columns have no collation, no opclass and no ordering
		 * options.
		 */
		if (attn >= nkeycols)
		{
			if (attribute->collation)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
						 errmsg("including column does not support a collation")));
			if (attribute->opclass)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
						 errmsg("including column does not support an operator class")));
			if (attribute->ordering != SORTBY_DEFAULT)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
						 errmsg("including column does not support ASC/DESC options")));
			if (attribute->nulls_ordering != SORTBY_NULLS_DEFAULT)
				ereport(ERROR,
						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
						 errmsg("including column does not support NULLS FIRST/LAST options")));

			classOidP[attn] = InvalidOid;
			colOptionP[attn] = 0;
			collationOidP[attn] = InvalidOid;
			attn++;

			continue;
		}

		/*
		 * Apply collation override if any
		 */
		if (attribute->collation)
			attcollation = get_collation_oid(attribute->collation, false);

		/*
		 * Check we have a collation iff it's a collatable type.  The only
		 * expected failures here are (1) COLLATE applied to a noncollatable
		 * type, or (2) index expression had an unresolved collation.  But we
		 * might as well code this to be a complete consistency check.
		 */
		if (type_is_collatable(atttype))
		{
			if (!OidIsValid(attcollation))
				ereport(ERROR,
						(errcode(ERRCODE_INDETERMINATE_COLLATION),
						 errmsg("could not determine which collation to use for index expression"),
						 errhint("Use the COLLATE clause to set the collation explicitly.")));
		}
		else
		{
			if (OidIsValid(attcollation))
				ereport(ERROR,
						(errcode(ERRCODE_DATATYPE_MISMATCH),
						 errmsg("collations are not supported by type %s",
								format_type_be(atttype))));
		}

		collationOidP[attn] = attcollation;

		/*
		 * Identify the opclass to use.
		 */
		classOidP[attn] = ResolveOpClass(attribute->opclass,
										 atttype,
										 accessMethodName,
										 accessMethodId);

		/*
		 * Identify the exclusion operator, if any.
		 */
		if (nextExclOp)
		{
			List	   *opname = (List *) lfirst(nextExclOp);
			Oid			opid;
			Oid			opfamily;
			int			strat;

			/*
			 * Find the operator --- it must accept the column datatype
			 * without runtime coercion (but binary compatibility is OK)
			 */
			opid = compatible_oper_opid(opname, atttype, atttype, false);

			/*
			 * Only allow commutative operators to be used in exclusion
			 * constraints. If X conflicts with Y, but Y does not conflict
			 * with X, bad things will happen.
			 */
			if (get_commutator(opid) != opid)
				ereport(ERROR,
						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
						 errmsg("operator %s is not commutative",
								format_operator(opid)),
						 errdetail("Only commutative operators can be used in exclusion constraints.")));

			/*
			 * Operator must be a member of the right opfamily, too
			 */
			opfamily = get_opclass_family(classOidP[attn]);
			strat = get_op_opfamily_strategy(opid, opfamily);
			if (strat == 0)
			{
				HeapTuple	opftuple;
				Form_pg_opfamily opfform;

				/*
				 * attribute->opclass might not explicitly name the opfamily,
				 * so fetch the name of the selected opfamily for use in the
				 * error message.
				 */
				opftuple = SearchSysCache1(OPFAMILYOID,
										   ObjectIdGetDatum(opfamily));
				if (!HeapTupleIsValid(opftuple))
					elog(ERROR, "cache lookup failed for opfamily %u",
						 opfamily);
				opfform = (Form_pg_opfamily) GETSTRUCT(opftuple);

				ereport(ERROR,
						(errcode(ERRCODE_WRONG_OBJECT_TYPE),
						 errmsg("operator %s is not a member of operator family \"%s\"",
								format_operator(opid),
								NameStr(opfform->opfname)),
						 errdetail("The exclusion operator must be related to the index operator class for the constraint.")));
			}

			indexInfo->ii_ExclusionOps[attn] = opid;
			indexInfo->ii_ExclusionProcs[attn] = get_opcode(opid);
			indexInfo->ii_ExclusionStrats[attn] = strat;
			nextExclOp = lnext(nextExclOp);
		}

		/*
		 * Set up the per-column options (indoption field).  For now, this is
		 * zero for any un-ordered index, while ordered indexes have DESC and
		 * NULLS FIRST/LAST options.
		 */
		colOptionP[attn] = 0;
		if (amcanorder)
		{
			/* default ordering is ASC */
			if (attribute->ordering == SORTBY_DESC)
				colOptionP[attn] |= INDOPTION_DESC;
			/* default null ordering is LAST for ASC, FIRST for DESC */
			if (attribute->nulls_ordering == SORTBY_NULLS_DEFAULT)
			{
				if (attribute->ordering == SORTBY_DESC)
					colOptionP[attn] |= INDOPTION_NULLS_FIRST;
			}
			else if (attribute->nulls_ordering == SORTBY_NULLS_FIRST)
				colOptionP[attn] |= INDOPTION_NULLS_FIRST;
		}
		else
		{
			/* index AM does not support ordering */
			if (attribute->ordering != SORTBY_DEFAULT)
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("access method \"%s\" does not support ASC/DESC options",
								accessMethodName)));
			if (attribute->nulls_ordering != SORTBY_NULLS_DEFAULT)
				ereport(ERROR,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("access method \"%s\" does not support NULLS FIRST/LAST options",
								accessMethodName)));
		}

		attn++;
	}
}

/*
 * Resolve possibly-defaulted operator class specification
 *
 * Note: This is used to resolve operator class specification in index and
 * partition key definitions.
 */
Oid
ResolveOpClass(List *opclass, Oid attrType,
			   const char *accessMethodName, Oid accessMethodId)
{
	char	   *schemaname;
	char	   *opcname;
	HeapTuple	tuple;
	Form_pg_opclass opform;
	Oid			opClassId,
				opInputType;

	/*
	 * Release 7.0 removed network_ops, timespan_ops, and datetime_ops, so we
	 * ignore those opclass names so the default *_ops is used.  This can be
	 * removed in some later release.  bjm 2000/02/07
	 *
	 * Release 7.1 removes lztext_ops, so suppress that too for a while.  tgl
	 * 2000/07/30
	 *
	 * Release 7.2 renames timestamp_ops to timestamptz_ops, so suppress that
	 * too for awhile.  I'm starting to think we need a better approach. tgl
	 * 2000/10/01
	 *
	 * Release 8.0 removes bigbox_ops (which was dead code for a long while
	 * anyway).  tgl 2003/11/11
	 */
	if (list_length(opclass) == 1)
	{
		char	   *claname = strVal(linitial(opclass));

		if (strcmp(claname, "network_ops") == 0 ||
			strcmp(claname, "timespan_ops") == 0 ||
			strcmp(claname, "datetime_ops") == 0 ||
			strcmp(claname, "lztext_ops") == 0 ||
			strcmp(claname, "timestamp_ops") == 0 ||
			strcmp(claname, "bigbox_ops") == 0)
			opclass = NIL;
	}

	if (opclass == NIL)
	{
		/* no operator class specified, so find the default */
		opClassId = GetDefaultOpClass(attrType, accessMethodId);
		if (!OidIsValid(opClassId))
		{
			/*
			 * In GPDB, this function is also used for DISTRIBUTED BY. That's why
			 * we've removed "for index" from the error message.
			 */
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_OBJECT),
					 errmsg("data type %s has no default operator class for access method \"%s\"",
							format_type_be(attrType), accessMethodName),
					 errhint("You must specify an operator class or define a default operator class for the data type.")));
		}
		return opClassId;
	}

	/*
	 * Specific opclass name given, so look up the opclass.
	 */

	/* deconstruct the name list */
	DeconstructQualifiedName(opclass, &schemaname, &opcname);

	if (schemaname)
	{
		/* Look in specific schema only */
		Oid			namespaceId;

		namespaceId = LookupExplicitNamespace(schemaname, false);
		tuple = SearchSysCache3(CLAAMNAMENSP,
								ObjectIdGetDatum(accessMethodId),
								PointerGetDatum(opcname),
								ObjectIdGetDatum(namespaceId));
	}
	else
	{
		/* Unqualified opclass name, so search the search path */
		opClassId = OpclassnameGetOpcid(accessMethodId, opcname);
		if (!OidIsValid(opClassId))
			ereport(ERROR,
					(errcode(ERRCODE_UNDEFINED_OBJECT),
					 errmsg("operator class \"%s\" does not exist for access method \"%s\"",
							opcname, accessMethodName)));
		tuple = SearchSysCache1(CLAOID, ObjectIdGetDatum(opClassId));
	}

	if (!HeapTupleIsValid(tuple))
		ereport(ERROR,
				(errcode(ERRCODE_UNDEFINED_OBJECT),
				 errmsg("operator class \"%s\" does not exist for access method \"%s\"",
						NameListToString(opclass), accessMethodName)));

	/*
	 * Verify that the index operator class accepts this datatype.  Note we
	 * will accept binary compatibility.
	 */
	opform = (Form_pg_opclass) GETSTRUCT(tuple);
	opClassId = opform->oid;
	opInputType = opform->opcintype;

	if (!IsBinaryCoercible(attrType, opInputType))
		ereport(ERROR,
				(errcode(ERRCODE_DATATYPE_MISMATCH),
				 errmsg("operator class \"%s\" does not accept data type %s",
						NameListToString(opclass), format_type_be(attrType))));

	ReleaseSysCache(tuple);

	return opClassId;
}

/*
 * GetDefaultOpClass
 *
 * Given the OIDs of a datatype and an access method, find the default
 * operator class, if any.  Returns InvalidOid if there is none.
 */
Oid
GetDefaultOpClass(Oid type_id, Oid am_id)
{
	Oid			result = InvalidOid;
	int			nexact = 0;
	int			ncompatible = 0;
	int			ncompatiblepreferred = 0;
	Relation	rel;
	ScanKeyData skey[1];
	SysScanDesc scan;
	HeapTuple	tup;
	TYPCATEGORY tcategory;

	/* If it's a domain, look at the base type instead */
	type_id = getBaseType(type_id);

	tcategory = TypeCategory(type_id);

	/*
	 * We scan through all the opclasses available for the access method,
	 * looking for one that is marked default and matches the target type
	 * (either exactly or binary-compatibly, but prefer an exact match).
	 *
	 * We could find more than one binary-compatible match.  If just one is
	 * for a preferred type, use that one; otherwise we fail, forcing the user
	 * to specify which one he wants.  (The preferred-type special case is a
	 * kluge for varchar: it's binary-compatible to both text and bpchar, so
	 * we need a tiebreaker.)  If we find more than one exact match, then
	 * someone put bogus entries in pg_opclass.
	 */
	rel = table_open(OperatorClassRelationId, AccessShareLock);

	ScanKeyInit(&skey[0],
				Anum_pg_opclass_opcmethod,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(am_id));

	scan = systable_beginscan(rel, OpclassAmNameNspIndexId, true,
							  NULL, 1, skey);

	while (HeapTupleIsValid(tup = systable_getnext(scan)))
	{
		Form_pg_opclass opclass = (Form_pg_opclass) GETSTRUCT(tup);

		/* ignore altogether if not a default opclass */
		if (!opclass->opcdefault)
			continue;
		if (opclass->opcintype == type_id)
		{
			nexact++;
			result = opclass->oid;
		}
		else if (nexact == 0 &&
				 IsBinaryCoercible(type_id, opclass->opcintype))
		{
			if (IsPreferredType(tcategory, opclass->opcintype))
			{
				ncompatiblepreferred++;
				result = opclass->oid;
			}
			else if (ncompatiblepreferred == 0)
			{
				ncompatible++;
				result = opclass->oid;
			}
		}
	}

	systable_endscan(scan);

	table_close(rel, AccessShareLock);

	/* raise error if pg_opclass contains inconsistent data */
	if (nexact > 1)
		ereport(ERROR,
				(errcode(ERRCODE_DUPLICATE_OBJECT),
				 errmsg("there are multiple default operator classes for data type %s",
						format_type_be(type_id))));

	if (nexact == 1 ||
		ncompatiblepreferred == 1 ||
		(ncompatiblepreferred == 0 && ncompatible == 1))
		return result;

	return InvalidOid;
}

/*
 *	makeObjectName()
 *
 *	Create a name for an implicitly created index, sequence, constraint,
 *	extended statistics, etc.
 *
 *	The parameters are typically: the original table name, the original field
 *	name, and a "type" string (such as "seq" or "pkey").    The field name
 *	and/or type can be NULL if not relevant.
 *
 *	The result is a palloc'd string.
 *
 *	The basic result we want is "name1_name2_label", omitting "_name2" or
 *	"_label" when those parameters are NULL.  However, we must generate
 *	a name with less than NAMEDATALEN characters!  So, we truncate one or
 *	both names if necessary to make a short-enough string.  The label part
 *	is never truncated (so it had better be reasonably short).
 *
 *	The caller is responsible for checking uniqueness of the generated
 *	name and retrying as needed; retrying will be done by altering the
 *	"label" string (which is why we never truncate that part).
 */
char *
makeObjectName(const char *name1, const char *name2, const char *label)
{
	char	   *name;
	int			overhead = 0;	/* chars needed for label and underscores */
	int			availchars;		/* chars available for name(s) */
	int			name1chars;		/* chars allocated to name1 */
	int			name2chars;		/* chars allocated to name2 */
	int			ndx;

	name1chars = strlen(name1);
	if (name2)
	{
		name2chars = strlen(name2);
		overhead++;				/* allow for separating underscore */
	}
	else
		name2chars = 0;
	if (label)
		overhead += strlen(label) + 1;

	availchars = NAMEDATALEN - 1 - overhead;
	Assert(availchars > 0);		/* else caller chose a bad label */

	/*
	 * If we must truncate,  preferentially truncate the longer name. This
	 * logic could be expressed without a loop, but it's simple and obvious as
	 * a loop.
	 */
	while (name1chars + name2chars > availchars)
	{
		if (name1chars > name2chars)
			name1chars--;
		else
			name2chars--;
	}

	name1chars = pg_mbcliplen(name1, name1chars, name1chars);
	if (name2)
		name2chars = pg_mbcliplen(name2, name2chars, name2chars);

	/* Now construct the string using the chosen lengths */
	name = palloc(name1chars + name2chars + overhead + 1);
	memcpy(name, name1, name1chars);
	ndx = name1chars;
	if (name2)
	{
		name[ndx++] = '_';
		memcpy(name + ndx, name2, name2chars);
		ndx += name2chars;
	}
	if (label)
	{
		name[ndx++] = '_';
		strcpy(name + ndx, label);
	}
	else
		name[ndx] = '\0';

	return name;
}

/*
 * Select a nonconflicting name for a new relation.  This is ordinarily
 * used to choose index names (which is why it's here) but it can also
 * be used for sequences, or any autogenerated relation kind.
 *
 * name1, name2, and label are used the same way as for makeObjectName(),
 * except that the label can't be NULL; digits will be appended to the label
 * if needed to create a name that is unique within the specified namespace.
 *
 * If isconstraint is true, we also avoid choosing a name matching any
 * existing constraint in the same namespace.  (This is stricter than what
 * Postgres itself requires, but the SQL standard says that constraint names
 * should be unique within schemas, so we follow that for autogenerated
 * constraint names.)
 *
 * Note: it is theoretically possible to get a collision anyway, if someone
 * else chooses the same name concurrently.  This is fairly unlikely to be
 * a problem in practice, especially if one is holding an exclusive lock on
 * the relation identified by name1.  However, if choosing multiple names
 * within a single command, you'd better create the new object and do
 * CommandCounterIncrement before choosing the next one!
 *
 * Returns a palloc'd string.
 */
char *
ChooseRelationName(const char *name1, const char *name2,
				   const char *label, Oid namespaceid,
				   bool isconstraint)
{
	int			pass = 0;
	char	   *relname = NULL;
	char		modlabel[NAMEDATALEN];

	if (GP_ROLE_EXECUTE == Gp_role)
		elog(ERROR, "relation names cannot be chosen on QE");

	/* try the unmodified label first */
	StrNCpy(modlabel, label, sizeof(modlabel));

	for (;;)
	{
		relname = makeObjectName(name1, name2, modlabel);

		if (!OidIsValid(get_relname_relid(relname, namespaceid)))
		{
			if (!isconstraint ||
				!ConstraintNameExists(relname, namespaceid))
				break;
		}

		/* found a conflict, so try a new name component */
		pfree(relname);
		snprintf(modlabel, sizeof(modlabel), "%s%d", label, ++pass);
	}

	return relname;
}

/*
 * Select the name to be used for an index.
 *
 * The argument list is pretty ad-hoc :-(
 */
char *
ChooseIndexName(const char *tabname, Oid namespaceId,
				List *colnames, List *exclusionOpNames,
				bool primary, bool isconstraint)
{
	char	   *indexname;

	if (primary)
	{
		/* the primary key's name does not depend on the specific column(s) */
		indexname = ChooseRelationName(tabname,
									   NULL,
									   "pkey",
									   namespaceId,
									   true);
	}
	else if (exclusionOpNames != NIL)
	{
		indexname = ChooseRelationName(tabname,
									   ChooseIndexNameAddition(colnames),
									   "excl",
									   namespaceId,
									   true);
	}
	else if (isconstraint)
	{
		indexname = ChooseRelationName(tabname,
									   ChooseIndexNameAddition(colnames),
									   "key",
									   namespaceId,
									   true);
	}
	else
	{
		indexname = ChooseRelationName(tabname,
									   ChooseIndexNameAddition(colnames),
									   "idx",
									   namespaceId,
									   false);
	}

	return indexname;
}

/*
 * Generate "name2" for a new index given the list of column names for it
 * (as produced by ChooseIndexColumnNames).  This will be passed to
 * ChooseRelationName along with the parent table name and a suitable label.
 *
 * We know that less than NAMEDATALEN characters will actually be used,
 * so we can truncate the result once we've generated that many.
 *
 * XXX See also ChooseForeignKeyConstraintNameAddition and
 * ChooseExtendedStatisticNameAddition.
 */
static char *
ChooseIndexNameAddition(List *colnames)
{
	char		buf[NAMEDATALEN * 2];
	int			buflen = 0;
	ListCell   *lc;

	buf[0] = '\0';
	foreach(lc, colnames)
	{
		const char *name = (const char *) lfirst(lc);

		if (buflen > 0)
			buf[buflen++] = '_';	/* insert _ between names */

		/*
		 * At this point we have buflen <= NAMEDATALEN.  name should be less
		 * than NAMEDATALEN already, but use strlcpy for paranoia.
		 */
		strlcpy(buf + buflen, name, NAMEDATALEN);
		buflen += strlen(buf + buflen);
		if (buflen >= NAMEDATALEN)
			break;
	}
	return pstrdup(buf);
}

/*
 * Select the actual names to be used for the columns of an index, given the
 * list of IndexElems for the columns.  This is mostly about ensuring the
 * names are unique so we don't get a conflicting-attribute-names error.
 *
 * Returns a List of plain strings (char *, not String nodes).
 */
List *
ChooseIndexColumnNames(List *indexElems)
{
	List	   *result = NIL;
	ListCell   *lc;

	foreach(lc, indexElems)
	{
		IndexElem  *ielem = (IndexElem *) lfirst(lc);
		const char *origname;
		const char *curname;
		int			i;
		char		buf[NAMEDATALEN];

		/* Get the preliminary name from the IndexElem */
		if (ielem->indexcolname)
			origname = ielem->indexcolname; /* caller-specified name */
		else if (ielem->name)
			origname = ielem->name; /* simple column reference */
		else
			origname = "expr";	/* default name for expression */

		/* If it conflicts with any previous column, tweak it */
		curname = origname;
		for (i = 1;; i++)
		{
			ListCell   *lc2;
			char		nbuf[32];
			int			nlen;

			foreach(lc2, result)
			{
				if (strcmp(curname, (char *) lfirst(lc2)) == 0)
					break;
			}
			if (lc2 == NULL)
				break;			/* found nonconflicting name */

			sprintf(nbuf, "%d", i);

			/* Ensure generated names are shorter than NAMEDATALEN */
			nlen = pg_mbcliplen(origname, strlen(origname),
								NAMEDATALEN - 1 - strlen(nbuf));
			memcpy(buf, origname, nlen);
			strcpy(buf + nlen, nbuf);
			curname = buf;
		}

		/* And attach to the result list */
		result = lappend(result, pstrdup(curname));
	}
	return result;
}

/*
 * ReindexIndex
 *		Recreate a specific index.
 */
void
ReindexIndex(ReindexStmt *stmt, bool isTopLevel)
{
	RangeVar   *indexRelation = stmt->relation;
	int			options = stmt->options;
	bool		concurrent = stmt->concurrent;
	struct ReindexIndexCallbackState state;
	Oid			indOid;
	char		persistence;
	char		relkind;

	/*
	 * On QE, we already know the index relation oid since we set it before
	 * dispatch the reindex statement.
	 * Other checks should already done on QD when calling RangeVarGetRelidExtended.
	 */
	if (Gp_role == GP_ROLE_EXECUTE)
	{
		Assert(OidIsValid(stmt->relid) && !concurrent);

		LockRelationOid(stmt->relid, AccessExclusiveLock);
		persistence = get_rel_persistence(stmt->relid);

		Assert(get_rel_relkind(stmt->relid) == RELKIND_INDEX);

		reindex_index(stmt->relid, false, persistence, options);
		return;
	}

	/*
	 * Find and lock index, and check permissions on table; use callback to
	 * obtain lock on table first, to avoid deadlock hazard.  The lock level
	 * used here must match the index lock obtained in reindex_index().
	 */
	state.concurrent = concurrent;
	state.locked_table_oid = InvalidOid;
	indOid = RangeVarGetRelidExtended(indexRelation,
									  concurrent ? ShareUpdateExclusiveLock : AccessExclusiveLock,
									  0,
									  RangeVarCallbackForReindexIndex,
									  &state);

	/*
	 * Obtain the current persistence and kind of the existing index.  We
	 * already hold a lock on the index.
	 */
	persistence = get_rel_persistence(indOid);
	relkind = get_rel_relkind(indOid);


	if (relkind == RELKIND_PARTITIONED_INDEX)
		ReindexPartitions(indOid, options, concurrent, isTopLevel);
	else if (concurrent &&
			 persistence != RELPERSISTENCE_TEMP)
		ReindexRelationConcurrently(indOid, options);
	else
		reindex_index(indOid, false, persistence, options);

	/*
	 * Reindex on partitioned index will do the reindex for each index in
	 * it's own transaction, so dispatch the statement under ReindexPartitions.
	 */
	if (Gp_role == GP_ROLE_DISPATCH && relkind != RELKIND_PARTITIONED_INDEX)
	{
		ReindexStmt	   *qestmt;

		qestmt = makeNode(ReindexStmt);
		qestmt->kind = REINDEX_OBJECT_INDEX;
		qestmt->relation = NULL;
		qestmt->options = options;
		qestmt->concurrent = concurrent;
		qestmt->relid = indOid;

		CdbDispatchUtilityStatement((Node *) qestmt,
									DF_CANCEL_ON_ERROR |
									DF_WITH_SNAPSHOT,
									GetAssignedOidsForDispatch(),
									NULL);
	}
}

/*
 * Check permissions on table before acquiring relation lock; also lock
 * the heap before the RangeVarGetRelidExtended takes the index lock, to avoid
 * deadlocks.
 */
static void
RangeVarCallbackForReindexIndex(const RangeVar *relation,
								Oid relId, Oid oldRelId, void *arg)
{
	char		relkind;
	struct ReindexIndexCallbackState *state = arg;
	LOCKMODE	table_lockmode;

	/*
	 * Lock level here should match table lock in reindex_index() for
	 * non-concurrent case and table locks used by index_concurrently_*() for
	 * concurrent case.
	 */
	table_lockmode = state->concurrent ? ShareUpdateExclusiveLock : ShareLock;

	/*
	 * If we previously locked some other index's heap, and the name we're
	 * looking up no longer refers to that relation, release the now-useless
	 * lock.
	 */
	if (relId != oldRelId && OidIsValid(oldRelId))
	{
		UnlockRelationOid(state->locked_table_oid, table_lockmode);
		state->locked_table_oid = InvalidOid;
	}

	/* If the relation does not exist, there's nothing more to do. */
	if (!OidIsValid(relId))
		return;

	/*
	 * If the relation does exist, check whether it's an index.  But note that
	 * the relation might have been dropped between the time we did the name
	 * lookup and now.  In that case, there's nothing to do.
	 */
	relkind = get_rel_relkind(relId);
	if (!relkind)
		return;
	if (relkind != RELKIND_INDEX &&
		relkind != RELKIND_PARTITIONED_INDEX)
		ereport(ERROR,
				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
				 errmsg("\"%s\" is not an index", relation->relname)));

	/* Check permissions */
	if (!pg_class_ownercheck(relId, GetUserId()))
		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_INDEX, relation->relname);

	/* Lock heap before index to avoid deadlock. */
	if (relId != oldRelId)
	{
		Oid			table_oid = IndexGetRelation(relId, true);

		/*
		 * If the OID isn't valid, it means the index was concurrently
		 * dropped, which is not a problem for us; just return normally.
		 */
		if (OidIsValid(table_oid))
		{
			LockRelationOid(table_oid, table_lockmode);
			state->locked_table_oid = table_oid;
		}
	}
}

/*
 * ReindexTable
 *		Recreate all indexes of a table (and of its toast table, if any)
 */
Oid
ReindexTable(ReindexStmt *stmt, bool isTopLevel)
{
	RangeVar   *relation = stmt->relation;
	int			options = stmt->options;
	bool		concurrent = stmt->concurrent;
	Oid			heapOid;
	bool		result;

	/*
	 * On QE, we already know the table relation oid since we set it before
	 * dispatch the reindex statement. reindex_relation will take care of the lock directly.
	 * Other checks should already done on QD when calling RangeVarGetRelidExtended.
	 */
	if (Gp_role == GP_ROLE_EXECUTE)
	{
		reindex_relation(stmt->relid,
						 REINDEX_REL_PROCESS_TOAST |
						 REINDEX_REL_CHECK_CONSTRAINTS,
						 options);
		return stmt->relid;
	}

	/*
	 * The lock level used here should match reindex_relation().
	 *
	 * If it's a temporary table, we will perform a non-concurrent reindex,
	 * even if CONCURRENTLY was requested.  In that case, reindex_relation()
	 * will upgrade the lock, but that's OK, because other sessions can't hold
	 * locks on our temporary table.
	 */
	heapOid = RangeVarGetRelidExtended(relation,
									   concurrent ? ShareUpdateExclusiveLock : ShareLock,
									   0,
									   RangeVarCallbackOwnsTable, NULL);

	if (get_rel_relkind(heapOid) == RELKIND_PARTITIONED_TABLE)
		ReindexPartitions(heapOid, options, concurrent, isTopLevel);
	else if (concurrent &&
			 get_rel_persistence(heapOid) != RELPERSISTENCE_TEMP)
	{
		result = ReindexRelationConcurrently(heapOid, options);

		if (!result)
			ereport(NOTICE,
					(errmsg("table \"%s\" has no indexes that can be reindexed concurrently",
							relation->relname)));
	}
	else
	{
		result = reindex_relation(heapOid,
								  REINDEX_REL_PROCESS_TOAST |
								  REINDEX_REL_CHECK_CONSTRAINTS,
								  options);
		if (!result)
			ereport(NOTICE,
					(errmsg("table \"%s\" has no indexes to reindex",
							relation->relname)));
	}

	/*
	 * Reindex on partitioned table will do the reindex for each index in
	 * it's own transaction, so dispatch the statement under ReindexPartitions.
	 */
	if (Gp_role == GP_ROLE_DISPATCH && get_rel_relkind(heapOid) != RELKIND_PARTITIONED_TABLE)
	{
		ReindexStmt	   *qestmt;

		qestmt = makeNode(ReindexStmt);
		qestmt->kind = REINDEX_OBJECT_TABLE;
		qestmt->relation = NULL;
		qestmt->options = options;
		qestmt->concurrent = concurrent;
		qestmt->relid = heapOid;

		CdbDispatchUtilityStatement((Node *) qestmt,
									DF_CANCEL_ON_ERROR |
									DF_WITH_SNAPSHOT,
									GetAssignedOidsForDispatch(),
									NULL);
	}

	return heapOid;
}

/*
 * ReindexMultipleTables
 *		Recreate indexes of tables selected by objectName/objectKind.
 *
 * To reduce the probability of deadlocks, each table is reindexed in a
 * separate transaction, so we can release the lock on it right away.
 * That means this must not be called within a user transaction block!
 */
void
ReindexMultipleTables(const char *objectName, ReindexObjectType objectKind,
					  int options, bool concurrent)
{
	Oid			objectOid;
	Relation	relationRelation;
	TableScanDesc scan;
	ScanKeyData scan_keys[1];
	HeapTuple	tuple;
	MemoryContext private_context;
	MemoryContext old;
	List	   *relids = NIL;
	int			num_keys;
	bool		concurrent_warning = false;

	Assert(Gp_role != GP_ROLE_EXECUTE);
	AssertArg(objectName);
	Assert(objectKind == REINDEX_OBJECT_SCHEMA ||
		   objectKind == REINDEX_OBJECT_SYSTEM ||
		   objectKind == REINDEX_OBJECT_DATABASE);

	if (objectKind == REINDEX_OBJECT_SYSTEM && concurrent)
		ereport(ERROR,
				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
				 errmsg("cannot reindex system catalogs concurrently")));

	SIMPLE_FAULT_INJECTOR("reindex_db");

	/*
	 * Get OID of object to reindex, being the database currently being used
	 * by session for a database or for system catalogs, or the schema defined
	 * by caller. At the same time do permission checks that need different
	 * processing depending on the object type.
	 */
	if (objectKind == REINDEX_OBJECT_SCHEMA)
	{
		objectOid = get_namespace_oid(objectName, false);

		if (!pg_namespace_ownercheck(objectOid, GetUserId()))
			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SCHEMA,
						   objectName);
	}
	else
	{
		objectOid = MyDatabaseId;

		if (strcmp(objectName, get_database_name(objectOid)) != 0)
			ereport(ERROR,
					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
					 errmsg("can only reindex the currently open database")));
		if (!pg_database_ownercheck(objectOid, GetUserId()))
			aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
						   objectName);
	}

	/*
	 * Create a memory context that will survive forced transaction commits we
	 * do below.  Since it is a child of PortalContext, it will go away
	 * eventually even if we suffer an error; there's no need for special
	 * abort cleanup logic.
	 */
	private_context = AllocSetContextCreate(PortalContext,
											"ReindexMultipleTables",
											ALLOCSET_SMALL_SIZES);

	/*
	 * Define the search keys to find the objects to reindex. For a schema, we
	 * select target relations using relnamespace, something not necessary for
	 * a database-wide operation.
	 */
	if (objectKind == REINDEX_OBJECT_SCHEMA)
	{
		num_keys = 1;
		ScanKeyInit(&scan_keys[0],
					Anum_pg_class_relnamespace,
					BTEqualStrategyNumber, F_OIDEQ,
					ObjectIdGetDatum(objectOid));
	}
	else
		num_keys = 0;

	/*
	 * Scan pg_class to build a list of the relations we need to reindex.
	 *
	 * We only consider plain relations and materialized views here (toast
	 * rels will be processed indirectly by reindex_relation).
	 */
	relationRelation = table_open(RelationRelationId, AccessShareLock);
	scan = table_beginscan_catalog(relationRelation, num_keys, scan_keys);
	while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
	{
		Form_pg_class classtuple = (Form_pg_class) GETSTRUCT(tuple);
		Oid			relid = classtuple->oid;

		/*
		 * Only regular tables and matviews can have indexes, so ignore any
		 * other kind of relation.
		 *
		 * Partitioned tables/indexes are skipped but matching leaf partitions
		 * are processed.
		 */
		if (classtuple->relkind != RELKIND_RELATION &&
			classtuple->relkind != RELKIND_MATVIEW)
			continue;

		/* Skip temp tables of other backends; we can't reindex them at all */
		if (classtuple->relpersistence == RELPERSISTENCE_TEMP &&
			!isTempNamespace(classtuple->relnamespace))
			continue;

		/* Check user/system classification, and optionally skip */
		if (objectKind == REINDEX_OBJECT_SYSTEM &&
			!IsSystemClass(relid, classtuple))
			continue;

		/*
		 * The table can be reindexed if the user is superuser, the table
		 * owner, or the database/schema owner (but in the latter case, only
		 * if it's not a shared relation).  pg_class_ownercheck includes the
		 * superuser case, and depending on objectKind we already know that
		 * the user has permission to run REINDEX on this database or schema
		 * per the permission checks at the beginning of this routine.
		 */
		if (classtuple->relisshared &&
			!pg_class_ownercheck(relid, GetUserId()))
			continue;

		/*
		 * Skip system tables, since index_create() would reject indexing them
		 * concurrently (and it would likely fail if we tried).
		 */
		if (concurrent &&
			IsCatalogRelationOid(relid))
		{
			if (!concurrent_warning)
				ereport(WARNING,
						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
						 errmsg("cannot reindex system catalogs concurrently, skipping all")));
			concurrent_warning = true;
			continue;
		}

		/* Save the list of relation OIDs in private context */
		old = MemoryContextSwitchTo(private_context);

		/*
		 * We always want to reindex pg_class first if it's selected to be
		 * reindexed.  This ensures that if there is any corruption in
		 * pg_class' indexes, they will be fixed before we process any other
		 * tables.  This is critical because reindexing itself will try to
		 * update pg_class.
		 */
		if (relid == RelationRelationId)
			relids = lcons_oid(relid, relids);
		else
			relids = lappend_oid(relids, relid);

		MemoryContextSwitchTo(old);
	}
	table_endscan(scan);
	table_close(relationRelation, AccessShareLock);

	/*
	 * Process each relation listed in a separate transaction.  Note that this
	 * commits and then starts a new transaction immediately.
	 */
	ReindexMultipleInternal(relids, options, concurrent);

	MemoryContextDelete(private_context);
}

/*
 * Error callback specific to ReindexPartitions().
 */
static void
reindex_error_callback(void *arg)
{
	ReindexErrorInfo *errinfo = (ReindexErrorInfo *) arg;

	Assert(errinfo->relkind == RELKIND_PARTITIONED_INDEX ||
		   errinfo->relkind == RELKIND_PARTITIONED_TABLE);

	if (errinfo->relkind == RELKIND_PARTITIONED_TABLE)
		errcontext("while reindexing partitioned table \"%s.%s\"",
				   errinfo->relnamespace, errinfo->relname);
	else if (errinfo->relkind == RELKIND_PARTITIONED_INDEX)
		errcontext("while reindexing partitioned index \"%s.%s\"",
				   errinfo->relnamespace, errinfo->relname);
}

/*
 * ReindexPartitions
 *
 * Reindex a set of partitions, per the partitioned index or table given
 * by the caller.
 */
static void
ReindexPartitions(Oid relid, int options, bool concurrent, bool isTopLevel)
{
	List	   *partitions = NIL;
	char		relkind = get_rel_relkind(relid);
	char	   *relname = get_rel_name(relid);
	char	   *relnamespace = get_namespace_name(get_rel_namespace(relid));
	MemoryContext reindex_context;
	List	   *inhoids;
	ListCell   *lc;
	ErrorContextCallback errcallback;
	ReindexErrorInfo errinfo;

	Assert(relkind == RELKIND_PARTITIONED_INDEX ||
		   relkind == RELKIND_PARTITIONED_TABLE);

	/*
	 * Check if this runs in a transaction block, with an error callback to
	 * provide more context under which a problem happens.
	 */
	errinfo.relname = pstrdup(relname);
	errinfo.relnamespace = pstrdup(relnamespace);
	errinfo.relkind = relkind;
	errcallback.callback = reindex_error_callback;
	errcallback.arg = (void *) &errinfo;
	errcallback.previous = error_context_stack;
	error_context_stack = &errcallback;

	PreventInTransactionBlock(isTopLevel,
							  relkind == RELKIND_PARTITIONED_TABLE ?
							  "REINDEX TABLE" : "REINDEX INDEX");

	/* Pop the error context stack */
	error_context_stack = errcallback.previous;

	/*
	 * Create special memory context for cross-transaction storage.
	 *
	 * Since it is a child of PortalContext, it will go away eventually even
	 * if we suffer an error so there is no need for special abort cleanup
	 * logic.
	 */
	reindex_context = AllocSetContextCreate(PortalContext, "Reindex",
											ALLOCSET_DEFAULT_SIZES);

	/* ShareLock is enough to prevent schema modifications */
	inhoids = find_all_inheritors(relid, ShareLock, NULL);

	/*
	 * The list of relations to reindex are the physical partitions of the
	 * tree so discard any partitioned table or index.
	 */
	foreach(lc, inhoids)
	{
		Oid			partoid = lfirst_oid(lc);
		char		partkind = get_rel_relkind(partoid);
		MemoryContext old_context;

		/*
		 * This discards partitioned tables, partitioned indexes and foreign
		 * tables.
		 */
		if (!RELKIND_HAS_STORAGE(partkind))
			continue;

		Assert(partkind == RELKIND_INDEX ||
			   partkind == RELKIND_RELATION);

		/* Save partition OID */
		old_context = MemoryContextSwitchTo(reindex_context);
		partitions = lappend_oid(partitions, partoid);
		MemoryContextSwitchTo(old_context);
	}

	/*
	 * Process each partition listed in a separate transaction.  Note that
	 * this commits and then starts a new transaction immediately.
	 */
	ReindexMultipleInternal(partitions, options, concurrent);

	/*
	 * Clean up working storage --- note we must do this after
	 * StartTransactionCommand, else we might be trying to delete the active
	 * context!
	 */
	MemoryContextDelete(reindex_context);
}

/*
 * ReindexMultipleInternal
 *
 * Reindex a list of relations, each one being processed in its own
 * transaction.  This commits the existing transaction immediately,
 * and starts a new transaction when finished.
 */
static void
ReindexMultipleInternal(List *relids, int options, bool concurrent)
{
	ListCell   *l;

	PopActiveSnapshot();
	CommitTransactionCommand();

	foreach(l, relids)
	{
		Oid			relid = lfirst_oid(l);
		Oid		heapId = InvalidOid;
		char		relkind;
		char		relpersistence;
		bool		result = false;
		LOCKMODE	lockmode;

		StartTransactionCommand();

		/* functions in indexes may want a snapshot set */
		PushActiveSnapshot(GetTransactionSnapshot());

		/* check if the relation still exists */
		if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(relid)))
		{
			PopActiveSnapshot();
			CommitTransactionCommand();
			continue;
		}

		relkind = get_rel_relkind(relid);
		relpersistence = get_rel_persistence(relid);
		lockmode = concurrent ? ShareUpdateExclusiveLock :
			   (relkind == RELKIND_INDEX ? AccessExclusiveLock : ShareLock);
		/*
 		 * If the relation is index, lock the table first to prevent dead lock.
 		 * ShareLock is sufficient since we only need to be sure no schema or
 		 * data changes are going on.
 		 */
		if (relkind == RELKIND_INDEX)
		{
			heapId = IndexGetRelation(relid, false);
			LockRelationOid(heapId, ShareLock);
		}
		LockRelationOid(relid, lockmode);
		/*
 		 * Now that we have the lock, double-check to see if the relation
 		 * really exists or not.  If not, assume it was dropped while we
 		 * waited to acquire lock, and ignore it.
 		 */
		if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(relid)))
		{
			UnlockRelationOid(relid, lockmode);
			if (OidIsValid(heapId))
				UnlockRelationOid(heapId, ShareLock);
			PopActiveSnapshot();
			CommitTransactionCommand();
			continue;
		}

		/*
		 * Partitioned tables and indexes can never be processed directly, and
		 * a list of their leaves should be built first.
		 */
		Assert(relkind != RELKIND_PARTITIONED_INDEX &&
			   relkind != RELKIND_PARTITIONED_TABLE);

		if (concurrent &&
			relpersistence != RELPERSISTENCE_TEMP)
		{
			result = ReindexRelationConcurrently(relid, options);
			/* ReindexRelationConcurrently() does the verbose output */
		}
		else if (relkind == RELKIND_INDEX)
		{
			reindex_index(relid, false, relpersistence,
						  options);
			PopActiveSnapshot();
			/* reindex_index() does the verbose output */
			result = true;
		}
		else
		{
			result = reindex_relation(relid,
									  REINDEX_REL_PROCESS_TOAST |
									  REINDEX_REL_CHECK_CONSTRAINTS,
									  options);

			if (result && (options & REINDEXOPT_VERBOSE))
				ereport(INFO,
						(errmsg("table \"%s.%s\" was reindexed",
								get_namespace_name(get_rel_namespace(relid)),
								get_rel_name(relid))));

			PopActiveSnapshot();
		}

		/* Dispatch a separate REINDEX command for each table. */
		if (result && Gp_role == GP_ROLE_DISPATCH)
		{
			ReindexStmt	   *stmt;

			stmt = makeNode(ReindexStmt);

			stmt->kind = relkind == RELKIND_INDEX ?
						 REINDEX_OBJECT_INDEX : REINDEX_OBJECT_TABLE;
			stmt->relation = NULL;
			stmt->options = options;
			stmt->concurrent = concurrent;
			stmt->relid = relid;

			PushActiveSnapshot(GetTransactionSnapshot());
			CdbDispatchUtilityStatement((Node *) stmt,
										DF_CANCEL_ON_ERROR |
										DF_WITH_SNAPSHOT,
										GetAssignedOidsForDispatch(),
										NULL);
			PopActiveSnapshot();
		}

		CommitTransactionCommand();
	}

	StartTransactionCommand();
}


/*
 * ReindexRelationConcurrently - process REINDEX CONCURRENTLY for given
 * relation OID
 *
 * 'relationOid' can either belong to an index, a table or a materialized
 * view.  For tables and materialized views, all its indexes will be rebuilt,
 * excluding invalid indexes and any indexes used in exclusion constraints,
 * but including its associated toast table indexes.  For indexes, the index
 * itself will be rebuilt.
 *
 * The locks taken on parent tables and involved indexes are kept until the
 * transaction is committed, at which point a session lock is taken on each
 * relation.  Both of these protect against concurrent schema changes.
 *
 * Returns true if any indexes have been rebuilt (including toast table's
 * indexes, when relevant), otherwise returns false.
 */
static bool
ReindexRelationConcurrently(Oid relationOid, int options)
{
	List	   *heapRelationIds = NIL;
	List	   *indexIds = NIL;
	List	   *newIndexIds = NIL;
	List	   *relationLocks = NIL;
	List	   *lockTags = NIL;
	ListCell   *lc,
			   *lc2;
	MemoryContext private_context;
	MemoryContext oldcontext;
	char		relkind;
	char	   *relationName = NULL;
	char	   *relationNamespace = NULL;
	PGRUsage	ru0;

	/*
	 * Create a memory context that will survive forced transaction commits we
	 * do below.  Since it is a child of PortalContext, it will go away
	 * eventually even if we suffer an error; there's no need for special
	 * abort cleanup logic.
	 */
	private_context = AllocSetContextCreate(PortalContext,
											"ReindexConcurrent",
											ALLOCSET_SMALL_SIZES);

	if (options & REINDEXOPT_VERBOSE)
	{
		/* Save data needed by REINDEX VERBOSE in private context */
		oldcontext = MemoryContextSwitchTo(private_context);

		relationName = get_rel_name(relationOid);
		relationNamespace = get_namespace_name(get_rel_namespace(relationOid));

		pg_rusage_init(&ru0);

		MemoryContextSwitchTo(oldcontext);
	}

	relkind = get_rel_relkind(relationOid);

	/*
	 * Extract the list of indexes that are going to be rebuilt based on the
	 * list of relation Oids given by caller.
	 */
	switch (relkind)
	{
		case RELKIND_RELATION:
		case RELKIND_MATVIEW:
		case RELKIND_TOASTVALUE:
			{
				/*
				 * In the case of a relation, find all its indexes including
				 * toast indexes.
				 */
				Relation	heapRelation;

				/* Save the list of relation OIDs in private context */
				oldcontext = MemoryContextSwitchTo(private_context);

				/* Track this relation for session locks */
				heapRelationIds = lappend_oid(heapRelationIds, relationOid);

				MemoryContextSwitchTo(oldcontext);

				if (IsCatalogRelationOid(relationOid))
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("cannot reindex system catalogs concurrently")));

				/* Open relation to get its indexes */
				heapRelation = table_open(relationOid, ShareUpdateExclusiveLock);

				/* Add all the valid indexes of relation to list */
				foreach(lc, RelationGetIndexList(heapRelation))
				{
					Oid			cellOid = lfirst_oid(lc);
					Relation	indexRelation = index_open(cellOid,
														   ShareUpdateExclusiveLock);

					if (!indexRelation->rd_index->indisvalid)
						ereport(WARNING,
								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
								 errmsg("cannot reindex invalid index \"%s.%s\" concurrently, skipping",
										get_namespace_name(get_rel_namespace(cellOid)),
										get_rel_name(cellOid))));
					else if (indexRelation->rd_index->indisexclusion)
						ereport(WARNING,
								(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
								 errmsg("cannot reindex exclusion constraint index \"%s.%s\" concurrently, skipping",
										get_namespace_name(get_rel_namespace(cellOid)),
										get_rel_name(cellOid))));
					else
					{
						/* Save the list of relation OIDs in private context */
						oldcontext = MemoryContextSwitchTo(private_context);

						indexIds = lappend_oid(indexIds, cellOid);

						MemoryContextSwitchTo(oldcontext);
					}

					index_close(indexRelation, NoLock);
				}

				/* Also add the toast indexes */
				if (OidIsValid(heapRelation->rd_rel->reltoastrelid))
				{
					Oid			toastOid = heapRelation->rd_rel->reltoastrelid;
					Relation	toastRelation = table_open(toastOid,
														   ShareUpdateExclusiveLock);

					/* Save the list of relation OIDs in private context */
					oldcontext = MemoryContextSwitchTo(private_context);

					/* Track this relation for session locks */
					heapRelationIds = lappend_oid(heapRelationIds, toastOid);

					MemoryContextSwitchTo(oldcontext);

					foreach(lc2, RelationGetIndexList(toastRelation))
					{
						Oid			cellOid = lfirst_oid(lc2);
						Relation	indexRelation = index_open(cellOid,
															   ShareUpdateExclusiveLock);

						if (!indexRelation->rd_index->indisvalid)
							ereport(WARNING,
									(errcode(ERRCODE_INDEX_CORRUPTED),
									 errmsg("cannot reindex invalid index \"%s.%s\" concurrently, skipping",
											get_namespace_name(get_rel_namespace(cellOid)),
											get_rel_name(cellOid))));
						else
						{
							/*
							 * Save the list of relation OIDs in private
							 * context
							 */
							oldcontext = MemoryContextSwitchTo(private_context);

							indexIds = lappend_oid(indexIds, cellOid);

							MemoryContextSwitchTo(oldcontext);
						}

						index_close(indexRelation, NoLock);
					}

					table_close(toastRelation, NoLock);
				}

				table_close(heapRelation, NoLock);
				break;
			}
		case RELKIND_INDEX:
			{
				Oid			heapId = IndexGetRelation(relationOid, false);

				if (IsCatalogRelationOid(heapId))
					ereport(ERROR,
							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
							 errmsg("cannot reindex system catalogs concurrently")));

				/* Save the list of relation OIDs in private context */
				oldcontext = MemoryContextSwitchTo(private_context);

				/* Track the heap relation of this index for session locks */
				heapRelationIds = list_make1_oid(heapId);

				/*
				 * Save the list of relation OIDs in private context.  Note
				 * that invalid indexes are allowed here.
				 */
				indexIds = lappend_oid(indexIds, relationOid);

				MemoryContextSwitchTo(oldcontext);
				break;
			}

		case RELKIND_PARTITIONED_TABLE:
		case RELKIND_PARTITIONED_INDEX:
		default:
			/* Return error if type of relation is not supported */
			ereport(ERROR,
					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
					 errmsg("cannot reindex this type of relation concurrently")));
			break;
	}

	/* Definitely no indexes, so leave */
	if (indexIds == NIL)
	{
		PopActiveSnapshot();
		return false;
	}

	Assert(heapRelationIds != NIL);

	/*-----
	 * Now we have all the indexes we want to process in indexIds.
	 *
	 * The phases now are:
	 *
	 * 1. create new indexes in the catalog
	 * 2. build new indexes
	 * 3. let new indexes catch up with tuples inserted in the meantime
	 * 4. swap index names
	 * 5. mark old indexes as dead
	 * 6. drop old indexes
	 *
	 * We process each phase for all indexes before moving to the next phase,
	 * for efficiency.
	 */

	/*
	 * Phase 1 of REINDEX CONCURRENTLY
	 *
	 * Create a new index with the same properties as the old one, but it is
	 * only registered in catalogs and will be built later.  Then get session
	 * locks on all involved tables.  See analogous code in DefineIndex() for
	 * more detailed comments.
	 */

	foreach(lc, indexIds)
	{
		char	   *concurrentName;
		Oid			indexId = lfirst_oid(lc);
		Oid			newIndexId;
		Relation	indexRel;
		Relation	heapRel;
		Relation	newIndexRel;
		LockRelId  *lockrelid;

		indexRel = index_open(indexId, ShareUpdateExclusiveLock);
		heapRel = table_open(indexRel->rd_index->indrelid,
							 ShareUpdateExclusiveLock);

		pgstat_progress_start_command(PROGRESS_COMMAND_CREATE_INDEX,
									  RelationGetRelid(heapRel));
		pgstat_progress_update_param(PROGRESS_CREATEIDX_COMMAND,
									 PROGRESS_CREATEIDX_COMMAND_REINDEX_CONCURRENTLY);
		pgstat_progress_update_param(PROGRESS_CREATEIDX_INDEX_OID,
									 indexId);
		pgstat_progress_update_param(PROGRESS_CREATEIDX_ACCESS_METHOD_OID,
									 indexRel->rd_rel->relam);

		/* Choose a temporary relation name for the new index */
		concurrentName = ChooseRelationName(get_rel_name(indexId),
											NULL,
											"ccnew",
											get_rel_namespace(indexRel->rd_index->indrelid),
											false);

		/* Create new index definition based on given index */
		newIndexId = index_concurrently_create_copy(heapRel,
													indexId,
													concurrentName);

		/* Now open the relation of the new index, a lock is also needed on it */
		newIndexRel = index_open(indexId, ShareUpdateExclusiveLock);

		/*
		 * Save the list of OIDs and locks in private context
		 */
		oldcontext = MemoryContextSwitchTo(private_context);

		newIndexIds = lappend_oid(newIndexIds, newIndexId);

		/*
		 * Save lockrelid to protect each relation from drop then close
		 * relations. The lockrelid on parent relation is not taken here to
		 * avoid multiple locks taken on the same relation, instead we rely on
		 * parentRelationIds built earlier.
		 */
		lockrelid = palloc(sizeof(*lockrelid));
		*lockrelid = indexRel->rd_lockInfo.lockRelId;
		relationLocks = lappend(relationLocks, lockrelid);
		lockrelid = palloc(sizeof(*lockrelid));
		*lockrelid = newIndexRel->rd_lockInfo.lockRelId;
		relationLocks = lappend(relationLocks, lockrelid);

		MemoryContextSwitchTo(oldcontext);

		index_close(indexRel, NoLock);
		index_close(newIndexRel, NoLock);
		table_close(heapRel, NoLock);
	}

	/*
	 * Save the heap lock for following visibility checks with other backends
	 * might conflict with this session.
	 */
	foreach(lc, heapRelationIds)
	{
		Relation	heapRelation = table_open(lfirst_oid(lc), ShareUpdateExclusiveLock);
		LockRelId  *lockrelid;
		LOCKTAG    *heaplocktag;

		/* Save the list of locks in private context */
		oldcontext = MemoryContextSwitchTo(private_context);

		/* Add lockrelid of heap relation to the list of locked relations */
		lockrelid = palloc(sizeof(*lockrelid));
		*lockrelid = heapRelation->rd_lockInfo.lockRelId;
		relationLocks = lappend(relationLocks, lockrelid);

		heaplocktag = (LOCKTAG *) palloc(sizeof(LOCKTAG));

		/* Save the LOCKTAG for this parent relation for the wait phase */
		SET_LOCKTAG_RELATION(*heaplocktag, lockrelid->dbId, lockrelid->relId);
		lockTags = lappend(lockTags, heaplocktag);

		MemoryContextSwitchTo(oldcontext);

		/* Close heap relation */
		table_close(heapRelation, NoLock);
	}

	/* Get a session-level lock on each table. */
	foreach(lc, relationLocks)
	{
		LockRelId  *lockrelid = (LockRelId *) lfirst(lc);

		LockRelationIdForSession(lockrelid, ShareUpdateExclusiveLock);
	}

	PopActiveSnapshot();
	CommitTransactionCommand();
	StartTransactionCommand();

	/*
	 * Phase 2 of REINDEX CONCURRENTLY
	 *
	 * Build the new indexes in a separate transaction for each index to avoid
	 * having open transactions for an unnecessary long time.  But before
	 * doing that, wait until no running transactions could have the table of
	 * the index open with the old list of indexes.  See "phase 2" in
	 * DefineIndex() for more details.
	 */

	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
								 PROGRESS_CREATEIDX_PHASE_WAIT_1);
	WaitForLockersMultiple(lockTags, ShareLock, true);
	CommitTransactionCommand();

	forboth(lc, indexIds, lc2, newIndexIds)
	{
		Relation	indexRel;
		Oid			oldIndexId = lfirst_oid(lc);
		Oid			newIndexId = lfirst_oid(lc2);
		Oid			heapId;

		CHECK_FOR_INTERRUPTS();

		/* Start new transaction for this index's concurrent build */
		StartTransactionCommand();

		/* Set ActiveSnapshot since functions in the indexes may need it */
		PushActiveSnapshot(GetTransactionSnapshot());

		/*
		 * Index relation has been closed by previous commit, so reopen it to
		 * get its information.
		 */
		indexRel = index_open(oldIndexId, ShareUpdateExclusiveLock);
		heapId = indexRel->rd_index->indrelid;
		index_close(indexRel, NoLock);

		/* Perform concurrent build of new index */
		index_concurrently_build(heapId, newIndexId);

		PopActiveSnapshot();
		CommitTransactionCommand();
	}
	StartTransactionCommand();

	/*
	 * Phase 3 of REINDEX CONCURRENTLY
	 *
	 * During this phase the old indexes catch up with any new tuples that
	 * were created during the previous phase.  See "phase 3" in DefineIndex()
	 * for more details.
	 */

	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
								 PROGRESS_CREATEIDX_PHASE_WAIT_2);
	WaitForLockersMultiple(lockTags, ShareLock, true);
	CommitTransactionCommand();

	foreach(lc, newIndexIds)
	{
		Oid			newIndexId = lfirst_oid(lc);
		Oid			heapId;
		TransactionId limitXmin;
		Snapshot	snapshot;

		CHECK_FOR_INTERRUPTS();

		StartTransactionCommand();

		heapId = IndexGetRelation(newIndexId, false);

		/*
		 * Take the "reference snapshot" that will be used by validate_index()
		 * to filter candidate tuples.
		 */
		snapshot = RegisterSnapshot(GetTransactionSnapshot());
		PushActiveSnapshot(snapshot);

		validate_index(heapId, newIndexId, snapshot);

		/*
		 * We can now do away with our active snapshot, we still need to save
		 * the xmin limit to wait for older snapshots.
		 */
		limitXmin = snapshot->xmin;

		PopActiveSnapshot();
		UnregisterSnapshot(snapshot);

		/*
		 * To ensure no deadlocks, we must commit and start yet another
		 * transaction, and do our wait before any snapshot has been taken in
		 * it.
		 */
		CommitTransactionCommand();
		StartTransactionCommand();

		/*
		 * The index is now valid in the sense that it contains all currently
		 * interesting tuples.  But since it might not contain tuples deleted
		 * just before the reference snap was taken, we have to wait out any
		 * transactions that might have older snapshots.
		 */
		pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
									 PROGRESS_CREATEIDX_PHASE_WAIT_3);
		WaitForOlderSnapshots(limitXmin, true);

		CommitTransactionCommand();
	}

	/*
	 * Phase 4 of REINDEX CONCURRENTLY
	 *
	 * Now that the new indexes have been validated, swap each new index with
	 * its corresponding old index.
	 *
	 * We mark the new indexes as valid and the old indexes as not valid at
	 * the same time to make sure we only get constraint violations from the
	 * indexes with the correct names.
	 */

	StartTransactionCommand();

	forboth(lc, indexIds, lc2, newIndexIds)
	{
		char	   *oldName;
		Oid			oldIndexId = lfirst_oid(lc);
		Oid			newIndexId = lfirst_oid(lc2);
		Oid			heapId;

		CHECK_FOR_INTERRUPTS();

		heapId = IndexGetRelation(oldIndexId, false);

		/* Choose a relation name for old index */
		oldName = ChooseRelationName(get_rel_name(oldIndexId),
									 NULL,
									 "ccold",
									 get_rel_namespace(heapId),
									 false);

		/*
		 * Swap old index with the new one.  This also marks the new one as
		 * valid and the old one as not valid.
		 */
		index_concurrently_swap(newIndexId, oldIndexId, oldName);

		/*
		 * Invalidate the relcache for the table, so that after this commit
		 * all sessions will refresh any cached plans that might reference the
		 * index.
		 */
		CacheInvalidateRelcacheByRelid(heapId);

		/*
		 * CCI here so that subsequent iterations see the oldName in the
		 * catalog and can choose a nonconflicting name for their oldName.
		 * Otherwise, this could lead to conflicts if a table has two indexes
		 * whose names are equal for the first NAMEDATALEN-minus-a-few
		 * characters.
		 */
		CommandCounterIncrement();
	}

	/* Commit this transaction and make index swaps visible */
	CommitTransactionCommand();
	StartTransactionCommand();

	/*
	 * Phase 5 of REINDEX CONCURRENTLY
	 *
	 * Mark the old indexes as dead.  First we must wait until no running
	 * transaction could be using the index for a query.  See also
	 * index_drop() for more details.
	 */

	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
								 PROGRESS_CREATEIDX_PHASE_WAIT_4);
	WaitForLockersMultiple(lockTags, AccessExclusiveLock, true);

	foreach(lc, indexIds)
	{
		Oid			oldIndexId = lfirst_oid(lc);
		Oid			heapId;

		CHECK_FOR_INTERRUPTS();
		heapId = IndexGetRelation(oldIndexId, false);
		index_concurrently_set_dead(heapId, oldIndexId);
	}

	/* Commit this transaction to make the updates visible. */
	CommitTransactionCommand();
	StartTransactionCommand();

	/*
	 * Phase 6 of REINDEX CONCURRENTLY
	 *
	 * Drop the old indexes.
	 */

	pgstat_progress_update_param(PROGRESS_CREATEIDX_PHASE,
								 PROGRESS_CREATEIDX_PHASE_WAIT_4);
	WaitForLockersMultiple(lockTags, AccessExclusiveLock, true);

	PushActiveSnapshot(GetTransactionSnapshot());

	{
		ObjectAddresses *objects = new_object_addresses();

		foreach(lc, indexIds)
		{
			Oid			oldIndexId = lfirst_oid(lc);
			ObjectAddress object;

			object.classId = RelationRelationId;
			object.objectId = oldIndexId;
			object.objectSubId = 0;

			add_exact_object_address(&object, objects);
		}

		/*
		 * Use PERFORM_DELETION_CONCURRENT_LOCK so that index_drop() uses the
		 * right lock level.
		 */
		performMultipleDeletions(objects, DROP_RESTRICT,
								 PERFORM_DELETION_CONCURRENT_LOCK | PERFORM_DELETION_INTERNAL);
	}

	PopActiveSnapshot();
	CommitTransactionCommand();

	/*
	 * Finally, release the session-level lock on the table.
	 */
	foreach(lc, relationLocks)
	{
		LockRelId  *lockrelid = (LockRelId *) lfirst(lc);

		UnlockRelationIdForSession(lockrelid, ShareUpdateExclusiveLock);
	}

	/* Start a new transaction to finish process properly */
	StartTransactionCommand();

	/* Log what we did */
	if (options & REINDEXOPT_VERBOSE)
	{
		if (relkind == RELKIND_INDEX)
			ereport(INFO,
					(errmsg("index \"%s.%s\" was reindexed",
							relationNamespace, relationName),
					 errdetail("%s.",
							   pg_rusage_show(&ru0))));
		else
		{
			foreach(lc, newIndexIds)
			{
				Oid			indOid = lfirst_oid(lc);

				ereport(INFO,
						(errmsg("index \"%s.%s\" was reindexed",
								get_namespace_name(get_rel_namespace(indOid)),
								get_rel_name(indOid))));
				/* Don't show rusage here, since it's not per index. */
			}

			ereport(INFO,
					(errmsg("table \"%s.%s\" was reindexed",
							relationNamespace, relationName),
					 errdetail("%s.",
							   pg_rusage_show(&ru0))));
		}
	}

	MemoryContextDelete(private_context);

	pgstat_progress_end_command();

	return true;
}

/*
 * Insert or delete an appropriate pg_inherits tuple to make the given index
 * be a partition of the indicated parent index.
 *
 * This also corrects the pg_depend information for the affected index.
 */
void
IndexSetParentIndex(Relation partitionIdx, Oid parentOid)
{
	Relation	pg_inherits;
	ScanKeyData key[2];
	SysScanDesc scan;
	Oid			partRelid = RelationGetRelid(partitionIdx);
	HeapTuple	tuple;
	bool		fix_dependencies;

	/* Make sure this is an index */
	Assert(partitionIdx->rd_rel->relkind == RELKIND_INDEX ||
		   partitionIdx->rd_rel->relkind == RELKIND_PARTITIONED_INDEX);

	/*
	 * Scan pg_inherits for rows linking our index to some parent.
	 */
	pg_inherits = relation_open(InheritsRelationId, RowExclusiveLock);
	ScanKeyInit(&key[0],
				Anum_pg_inherits_inhrelid,
				BTEqualStrategyNumber, F_OIDEQ,
				ObjectIdGetDatum(partRelid));
	ScanKeyInit(&key[1],
				Anum_pg_inherits_inhseqno,
				BTEqualStrategyNumber, F_INT4EQ,
				Int32GetDatum(1));
	scan = systable_beginscan(pg_inherits, InheritsRelidSeqnoIndexId, true,
							  NULL, 2, key);
	tuple = systable_getnext(scan);

	if (!HeapTupleIsValid(tuple))
	{
		if (parentOid == InvalidOid)
		{
			/*
			 * No pg_inherits row, and no parent wanted: nothing to do in this
			 * case.
			 */
			fix_dependencies = false;
		}
		else
		{
			Datum		values[Natts_pg_inherits];
			bool		isnull[Natts_pg_inherits];

			/*
			 * No pg_inherits row exists, and we want a parent for this index,
			 * so insert it.
			 */
			values[Anum_pg_inherits_inhrelid - 1] = ObjectIdGetDatum(partRelid);
			values[Anum_pg_inherits_inhparent - 1] =
				ObjectIdGetDatum(parentOid);
			values[Anum_pg_inherits_inhseqno - 1] = Int32GetDatum(1);
			memset(isnull, false, sizeof(isnull));

			tuple = heap_form_tuple(RelationGetDescr(pg_inherits),
									values, isnull);
			CatalogTupleInsert(pg_inherits, tuple);

			fix_dependencies = true;
		}
	}
	else
	{
		Form_pg_inherits inhForm = (Form_pg_inherits) GETSTRUCT(tuple);

		if (parentOid == InvalidOid)
		{
			/*
			 * There exists a pg_inherits row, which we want to clear; do so.
			 */
			CatalogTupleDelete(pg_inherits, &tuple->t_self);
			fix_dependencies = true;
		}
		else
		{
			/*
			 * A pg_inherits row exists.  If it's the same we want, then we're
			 * good; if it differs, that amounts to a corrupt catalog and
			 * should not happen.
			 */
			if (inhForm->inhparent != parentOid)
			{
				/* unexpected: we should not get called in this case */
				elog(ERROR, "bogus pg_inherit row: inhrelid %u inhparent %u",
					 inhForm->inhrelid, inhForm->inhparent);
			}

			/* already in the right state */
			fix_dependencies = false;
		}
	}

	/* done with pg_inherits */
	systable_endscan(scan);
	relation_close(pg_inherits, RowExclusiveLock);

	/* set relhassubclass if an index partition has been added to the parent */
	if (OidIsValid(parentOid))
		SetRelationHasSubclass(parentOid, true);

	/* set relispartition correctly on the partition */
	update_relispartition(partRelid, OidIsValid(parentOid));

	if (fix_dependencies)
	{
		/*
		 * Insert/delete pg_depend rows.  If setting a parent, add PARTITION
		 * dependencies on the parent index and the table; if removing a
		 * parent, delete PARTITION dependencies.
		 */
		if (OidIsValid(parentOid))
		{
			ObjectAddress partIdx;
			ObjectAddress parentIdx;
			ObjectAddress partitionTbl;

			ObjectAddressSet(partIdx, RelationRelationId, partRelid);
			ObjectAddressSet(parentIdx, RelationRelationId, parentOid);
			ObjectAddressSet(partitionTbl, RelationRelationId,
							 partitionIdx->rd_index->indrelid);
			recordDependencyOn(&partIdx, &parentIdx,
							   DEPENDENCY_PARTITION_PRI);
			recordDependencyOn(&partIdx, &partitionTbl,
							   DEPENDENCY_PARTITION_SEC);
		}
		else
		{
			deleteDependencyRecordsForClass(RelationRelationId, partRelid,
											RelationRelationId,
											DEPENDENCY_PARTITION_PRI);
			deleteDependencyRecordsForClass(RelationRelationId, partRelid,
											RelationRelationId,
											DEPENDENCY_PARTITION_SEC);
		}

		/* make our updates visible */
		CommandCounterIncrement();
	}
}

/*
 * Subroutine of IndexSetParentIndex to update the relispartition flag of the
 * given index to the given value.
 */
static void
update_relispartition(Oid relationId, bool newval)
{
	HeapTuple	tup;
	Relation	classRel;

	classRel = table_open(RelationRelationId, RowExclusiveLock);
	tup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relationId));
	if (!HeapTupleIsValid(tup))
		elog(ERROR, "cache lookup failed for relation %u", relationId);
	Assert(((Form_pg_class) GETSTRUCT(tup))->relispartition != newval);
	((Form_pg_class) GETSTRUCT(tup))->relispartition = newval;
	CatalogTupleUpdate(classRel, &tup->t_self, tup);
	heap_freetuple(tup);
	table_close(classRel, RowExclusiveLock);
}

相关信息

greenplumn 源码目录

相关文章

greenplumn aggregatecmds 源码

greenplumn alter 源码

greenplumn amcmds 源码

greenplumn analyze 源码

greenplumn analyzefuncs 源码

greenplumn analyzeutils 源码

greenplumn async 源码

greenplumn cluster 源码

greenplumn collationcmds 源码

greenplumn comment 源码

0  赞