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Partial indexes work again, courtesy of Martijn van Oosterhout.
Note: I didn't force an initdb, figuring that one today was enough. However, there is a new function in pg_proc.h, and pg_dump won't be able to dump partial indexes until you add that function.
This commit is contained in:
Tom Lane
@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.51 2001/07/15 22:48:17 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/commands/indexcmds.c,v 1.52 2001/07/16 05:06:57 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -45,8 +45,6 @@
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/* non-export function prototypes */
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static void CheckPredicate(List *predList, List *rangeTable, Oid baseRelOid);
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static void CheckPredExpr(Node *predicate, List *rangeTable, Oid baseRelOid);
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static void CheckPredClause(Expr *predicate, List *rangeTable, Oid baseRelOid);
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static void FuncIndexArgs(IndexInfo *indexInfo, Oid *classOidP,
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IndexElem *funcIndex,
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Oid relId,
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@ -144,12 +142,8 @@ DefineIndex(char *heapRelationName,
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}
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/*
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* Convert the partial-index predicate from parsetree form to plan
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* form, so it can be readily evaluated during index creation. Note:
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* "predicate" comes in as a list containing (1) the predicate itself
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* (a where_clause), and (2) a corresponding range table.
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*
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* [(1) is 'predicate' and (2) is 'rangetable' now. - ay 10/94]
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* Convert the partial-index predicate from parsetree form to
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* an implicit-AND qual expression, for easier evaluation at runtime.
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*/
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if (predicate != NULL && rangetable != NIL)
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{
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@ -166,7 +160,7 @@ DefineIndex(char *heapRelationName,
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* structure
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*/
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indexInfo = makeNode(IndexInfo);
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indexInfo->ii_Predicate = (Node *) cnfPred;
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indexInfo->ii_Predicate = cnfPred;
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indexInfo->ii_FuncOid = InvalidOid;
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indexInfo->ii_Unique = unique;
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@ -218,155 +212,30 @@ DefineIndex(char *heapRelationName,
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}
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/*
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* ExtendIndex
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* Extends a partial index.
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*/
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void
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ExtendIndex(char *indexRelationName, Expr *predicate, List *rangetable)
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{
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Relation heapRelation;
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Relation indexRelation;
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Oid accessMethodId,
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indexId,
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relationId;
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HeapTuple tuple;
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Form_pg_index index;
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List *cnfPred = NIL;
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IndexInfo *indexInfo;
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Node *oldPred;
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/*
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* Get index's relation id and access method id from pg_class
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*/
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tuple = SearchSysCache(RELNAME,
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PointerGetDatum(indexRelationName),
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0, 0, 0);
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if (!HeapTupleIsValid(tuple))
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elog(ERROR, "ExtendIndex: index \"%s\" not found",
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indexRelationName);
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indexId = tuple->t_data->t_oid;
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accessMethodId = ((Form_pg_class) GETSTRUCT(tuple))->relam;
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ReleaseSysCache(tuple);
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/*
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* Extract info from the pg_index tuple for the index
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*/
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tuple = SearchSysCache(INDEXRELID,
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ObjectIdGetDatum(indexId),
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0, 0, 0);
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if (!HeapTupleIsValid(tuple))
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elog(ERROR, "ExtendIndex: relation \"%s\" is not an index",
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indexRelationName);
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index = (Form_pg_index) GETSTRUCT(tuple);
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Assert(index->indexrelid == indexId);
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relationId = index->indrelid;
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indexInfo = BuildIndexInfo(tuple);
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oldPred = indexInfo->ii_Predicate;
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ReleaseSysCache(tuple);
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if (oldPred == NULL)
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elog(ERROR, "ExtendIndex: \"%s\" is not a partial index",
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indexRelationName);
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/*
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* Convert the extension predicate from parsetree form to plan form,
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* so it can be readily evaluated during index creation. Note:
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* "predicate" comes in two parts (1) the predicate expression itself,
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* and (2) a corresponding range table.
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*
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* XXX I think this code is broken --- index_build expects a single
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* expression not a list --- tgl Jul 00
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*/
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if (rangetable != NIL)
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{
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cnfPred = cnfify((Expr *) copyObject(predicate), true);
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fix_opids((Node *) cnfPred);
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CheckPredicate(cnfPred, rangetable, relationId);
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}
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/* pass new predicate to index_build */
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indexInfo->ii_Predicate = (Node *) cnfPred;
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/* Open heap and index rels, and get suitable locks */
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heapRelation = heap_open(relationId, ShareLock);
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indexRelation = index_open(indexId);
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/* Obtain exclusive lock on it, just to be sure */
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LockRelation(indexRelation, AccessExclusiveLock);
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InitIndexStrategy(indexInfo->ii_NumIndexAttrs,
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indexRelation, accessMethodId);
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/*
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* XXX currently BROKEN: if we want to support EXTEND INDEX, oldPred
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* needs to be passed through to IndexBuildHeapScan. We could do this
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* without help from the index AMs if we added an oldPred field to the
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* IndexInfo struct. Currently I'm expecting that EXTEND INDEX will
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* get removed, so I'm not going to do that --- tgl 7/14/01
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*/
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index_build(heapRelation, indexRelation, indexInfo);
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/* heap and index rels are closed as a side-effect of index_build */
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}
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/*
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* CheckPredicate
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* Checks that the given list of partial-index predicates refer
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* (via the given range table) only to the given base relation oid,
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* and that they're in a form the planner can handle, i.e.,
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* boolean combinations of "ATTR OP CONST" (yes, for now, the ATTR
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* has to be on the left).
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* (via the given range table) only to the given base relation oid.
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*
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* This used to also constrain the form of the predicate to forms that
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* indxpath.c could do something with. However, that seems overly
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* restrictive. One useful application of partial indexes is to apply
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* a UNIQUE constraint across a subset of a table, and in that scenario
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* any evaluatable predicate will work. So accept any predicate here
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* (except ones requiring a plan), and let indxpath.c fend for itself.
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*/
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static void
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CheckPredicate(List *predList, List *rangeTable, Oid baseRelOid)
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{
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List *item;
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foreach(item, predList)
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CheckPredExpr(lfirst(item), rangeTable, baseRelOid);
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}
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static void
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CheckPredExpr(Node *predicate, List *rangeTable, Oid baseRelOid)
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{
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List *clauses = NIL,
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*clause;
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if (is_opclause(predicate))
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{
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CheckPredClause((Expr *) predicate, rangeTable, baseRelOid);
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return;
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}
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else if (or_clause(predicate) || and_clause(predicate))
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clauses = ((Expr *) predicate)->args;
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else
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elog(ERROR, "Unsupported partial-index predicate expression type");
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foreach(clause, clauses)
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CheckPredExpr(lfirst(clause), rangeTable, baseRelOid);
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}
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static void
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CheckPredClause(Expr *predicate, List *rangeTable, Oid baseRelOid)
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{
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Var *pred_var;
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Const *pred_const;
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pred_var = (Var *) get_leftop(predicate);
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pred_const = (Const *) get_rightop(predicate);
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if (!IsA(predicate->oper, Oper) ||
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!IsA(pred_var, Var) ||
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!IsA(pred_const, Const))
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elog(ERROR, "Unsupported partial-index predicate clause type");
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if (getrelid(pred_var->varno, rangeTable) != baseRelOid)
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if (length(rangeTable) != 1 || getrelid(1, rangeTable) != baseRelOid)
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elog(ERROR,
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"Partial-index predicates may refer only to the base relation");
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"Partial-index predicates may refer only to the base relation");
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if (contain_subplans((Node *) predList))
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elog(ERROR, "Cannot use subselect in index predicate");
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if (contain_agg_clause((Node *) predList))
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elog(ERROR, "Cannot use aggregate in index predicate");
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}
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