diff options
Diffstat (limited to 'src/backend/executor/nodeMergejoin.c')
| -rw-r--r-- | src/backend/executor/nodeMergejoin.c | 40 |
1 files changed, 19 insertions, 21 deletions
diff --git a/src/backend/executor/nodeMergejoin.c b/src/backend/executor/nodeMergejoin.c index 63e9035f546..a5f08c28ef3 100644 --- a/src/backend/executor/nodeMergejoin.c +++ b/src/backend/executor/nodeMergejoin.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/executor/nodeMergejoin.c,v 1.84 2007/01/05 22:19:28 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/executor/nodeMergejoin.c,v 1.85 2007/01/10 18:06:02 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -156,35 +156,36 @@ typedef struct MergeJoinClauseData * the two expressions from the original clause. * * In addition to the expressions themselves, the planner passes the btree - * opfamily OID and btree strategy number (BTLessStrategyNumber or - * BTGreaterStrategyNumber) that identify the intended merge semantics for - * each merge key. The mergejoinable operator is an equality operator in - * this opfamily, and the two inputs are guaranteed to be ordered in either - * increasing or decreasing (respectively) order according to this opfamily. - * This allows us to obtain the needed comparison functions from the opfamily. + * opfamily OID, btree strategy number (BTLessStrategyNumber or + * BTGreaterStrategyNumber), and nulls-first flag that identify the intended + * merge semantics for each merge key. The mergejoinable operator is an + * equality operator in this opfamily, and the two inputs are guaranteed to be + * ordered in either increasing or decreasing (respectively) order according + * to this opfamily. This allows us to obtain the needed comparison functions + * from the opfamily. */ static MergeJoinClause -MJExamineQuals(List *mergeclauses, List *mergefamilies, List *mergestrategies, +MJExamineQuals(List *mergeclauses, + Oid *mergefamilies, + int *mergestrategies, + bool *mergenullsfirst, PlanState *parent) { MergeJoinClause clauses; int nClauses = list_length(mergeclauses); int iClause; ListCell *cl; - ListCell *cf; - ListCell *cs; clauses = (MergeJoinClause) palloc0(nClauses * sizeof(MergeJoinClauseData)); iClause = 0; - cf = list_head(mergefamilies); - cs = list_head(mergestrategies); foreach(cl, mergeclauses) { OpExpr *qual = (OpExpr *) lfirst(cl); MergeJoinClause clause = &clauses[iClause]; - Oid opfamily; - StrategyNumber opstrategy; + Oid opfamily = mergefamilies[iClause]; + StrategyNumber opstrategy = mergestrategies[iClause]; + bool nulls_first = mergenullsfirst[iClause]; int op_strategy; Oid op_lefttype; Oid op_righttype; @@ -192,14 +193,10 @@ MJExamineQuals(List *mergeclauses, List *mergefamilies, List *mergestrategies, RegProcedure cmpproc; AclResult aclresult; - opfamily = lfirst_oid(cf); - cf = lnext(cf); - opstrategy = lfirst_int(cs); - cs = lnext(cs); - /* Later we'll support both ascending and descending sort... */ Assert(opstrategy == BTLessStrategyNumber); clause->cmpstrategy = MERGEFUNC_CMP; + Assert(!nulls_first); if (!IsA(qual, OpExpr)) elog(ERROR, "mergejoin clause is not an OpExpr"); @@ -1525,8 +1522,9 @@ ExecInitMergeJoin(MergeJoin *node, EState *estate, int eflags) */ mergestate->mj_NumClauses = list_length(node->mergeclauses); mergestate->mj_Clauses = MJExamineQuals(node->mergeclauses, - node->mergefamilies, - node->mergestrategies, + node->mergeFamilies, + node->mergeStrategies, + node->mergeNullsFirst, (PlanState *) mergestate); /* |