diff options
Diffstat (limited to 'src/backend/optimizer')
| -rw-r--r-- | src/backend/optimizer/plan/createplan.c | 23 | ||||
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 28 | ||||
| -rw-r--r-- | src/backend/optimizer/plan/setrefs.c | 3 | ||||
| -rw-r--r-- | src/backend/optimizer/plan/subselect.c | 3 |
4 files changed, 45 insertions, 12 deletions
diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index eb005121cd5..a865da61b92 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.98 2000/10/05 19:11:29 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.99 2000/10/26 21:36:09 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -1651,6 +1651,27 @@ make_setop(SetOpCmd cmd, List *tlist, Plan *lefttree, return node; } +Limit * +make_limit(List *tlist, Plan *lefttree, + Node *limitOffset, Node *limitCount) +{ + Limit *node = makeNode(Limit); + Plan *plan = &node->plan; + + copy_plan_costsize(plan, lefttree); + + plan->state = (EState *) NULL; + plan->targetlist = tlist; + plan->qual = NIL; + plan->lefttree = lefttree; + plan->righttree = NULL; + + node->limitOffset = limitOffset; + node->limitCount = limitCount; + + return node; +} + Result * make_result(List *tlist, Node *resconstantqual, diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index d73ca9a34ac..f9c70f7137d 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.92 2000/10/05 19:11:29 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.93 2000/10/26 21:36:09 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -341,8 +341,6 @@ is_simple_subquery(Query *subquery) */ if (subquery->rowMarks) elog(ERROR, "FOR UPDATE is not supported in subselects"); - if (subquery->limitOffset || subquery->limitCount) - elog(ERROR, "LIMIT is not supported in subselects"); /* * Can't currently pull up a query with setops. * Maybe after querytree redesign... @@ -350,13 +348,16 @@ is_simple_subquery(Query *subquery) if (subquery->setOperations) return false; /* - * Can't pull up a subquery involving grouping, aggregation, or sorting. + * Can't pull up a subquery involving grouping, aggregation, sorting, + * or limiting. */ if (subquery->hasAggs || subquery->groupClause || subquery->havingQual || subquery->sortClause || - subquery->distinctClause) + subquery->distinctClause || + subquery->limitOffset || + subquery->limitCount) return false; /* * Hack: don't try to pull up a subquery with an empty jointree. @@ -831,7 +832,7 @@ union_planner(Query *parse, } else { - /* It's a PARAM ... punt ... */ + /* It's an expression ... punt ... */ tuple_fraction = 0.10; } } @@ -839,9 +840,8 @@ union_planner(Query *parse, } else { - /* - * COUNT is a PARAM ... don't know exactly what the + * COUNT is an expression ... don't know exactly what the * limit will be, but for lack of a better idea assume * 10% of the plan's result is wanted. */ @@ -1024,7 +1024,7 @@ union_planner(Query *parse, } /* - * Finally, if there is a DISTINCT clause, add the UNIQUE node. + * If there is a DISTINCT clause, add the UNIQUE node. */ if (parse->distinctClause) { @@ -1032,6 +1032,16 @@ union_planner(Query *parse, parse->distinctClause); } + /* + * Finally, if there is a LIMIT/OFFSET clause, add the LIMIT node. + */ + if (parse->limitOffset || parse->limitCount) + { + result_plan = (Plan *) make_limit(tlist, result_plan, + parse->limitOffset, + parse->limitCount); + } + return result_plan; } diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c index 14c9dad3ef3..deb020e2565 100644 --- a/src/backend/optimizer/plan/setrefs.c +++ b/src/backend/optimizer/plan/setrefs.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.67 2000/10/05 19:11:29 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.68 2000/10/26 21:36:09 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -139,6 +139,7 @@ set_plan_references(Plan *plan) case T_Sort: case T_Unique: case T_SetOp: + case T_Limit: case T_Hash: /* diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c index 03e38371df5..296164acb89 100644 --- a/src/backend/optimizer/plan/subselect.c +++ b/src/backend/optimizer/plan/subselect.c @@ -7,7 +7,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/subselect.c,v 1.43 2000/10/05 19:11:29 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/subselect.c,v 1.44 2000/10/26 21:36:09 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -657,6 +657,7 @@ SS_finalize_plan(Plan *plan) case T_Sort: case T_Unique: case T_SetOp: + case T_Limit: case T_Group: break; |