From 6231e161c95a0bb1f40fa2693189fdd356095793 Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Wed, 24 Dec 1997 06:06:58 +0000 Subject: [PATCH] Implementation of UNIONs. --- src/backend/nodes/copyfuncs.c | 15 +++++- src/backend/optimizer/plan/planner.c | 20 +++++--- src/backend/optimizer/prep/prepunion.c | 71 ++++++++++++++------------ src/backend/parser/analyze.c | 30 ++++++----- src/backend/parser/gram.y | 26 ++++------ src/include/nodes/parsenodes.h | 20 ++------ src/include/optimizer/prep.h | 4 +- 7 files changed, 95 insertions(+), 91 deletions(-) diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c index f7a88a54b2..96dc5097e1 100644 --- a/src/backend/nodes/copyfuncs.c +++ b/src/backend/nodes/copyfuncs.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.25 1997/12/23 21:49:03 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.26 1997/12/24 06:05:52 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -1566,7 +1566,18 @@ _copyQuery(Query *from) } else newnode->qry_aggs = NULL; - + + if (from->unionClause) + { + List *ulist, *temp_list = NIL; + + foreach(ulist, from->unionClause) + temp_list = lappend(temp_list,copyObject(lfirst(ulist))); + newnode->unionClause = temp_list; + } + else + newnode->unionClause = NULL; + return newnode; } diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index ddfc428917..cc3d9dfd7f 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.15 1997/12/22 05:42:08 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.16 1997/12/24 06:06:01 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -81,11 +81,19 @@ planner(Query *parse) int rt_index; - /* - * plan inheritance - */ - rt_index = first_matching_rt_entry(rangetable, INHERITS_FLAG); - if (rt_index != -1) + if (parse->unionClause) + { + result_plan = (Plan *) plan_union_queries(0, /* none */ + parse, + UNION_FLAG); + /* XXX do we need to do this? bjm 12/19/97 */ + tlist = preprocess_targetlist(tlist, + parse->commandType, + parse->resultRelation, + parse->rtable); + } + else if ((rt_index = + first_matching_rt_entry(rangetable, INHERITS_FLAG)) != -1) { result_plan = (Plan *) plan_union_queries((Index) rt_index, parse, diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index 11e9489942..877e4c8654 100644 --- a/src/backend/optimizer/prep/prepunion.c +++ b/src/backend/optimizer/prep/prepunion.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.12 1997/12/21 05:18:28 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.13 1997/12/24 06:06:07 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -149,20 +149,51 @@ plan_union_queries(Index rt_index, find_all_inheritors(lconsi(rt_entry->relid, NIL), NIL); + /* + * Remove the flag for this relation, since we're about to handle it + * (do it before recursing!). XXX destructive parse tree change + */ + switch (flag) + { + case INHERITS_FLAG: + rt_fetch(rt_index, rangetable)->inh = false; + break; + default: + break; + } + + /* + * XXX - can't find any reason to sort union-relids as paul did, so + * we're leaving it out for now (maybe forever) - jeff & lp + * + * [maybe so. btw, jeff & lp did the lisp conversion, according to Paul. + * -- ay 10/94.] + */ + union_plans = plan_union_query(union_relids, rt_index, rt_entry, + parse, flag, &union_rt_entries); + + return (make_append(union_plans, + rt_index, + union_rt_entries, + ((Plan *) lfirst(union_plans))->targetlist)); break; - -#if 0 + case UNION_FLAG: { - Index rt_index = 0; + List *ulist, *hold_union, *union_plans; - union_plans = handleunion(root, rangetable, tlist, qual); + hold_union = parse->unionClause; + parse->unionClause = NULL; /* prevent looping */ + + union_plans = lcons(planner(parse), NIL); + + foreach(ulist, hold_union) + union_plans = lappend(union_plans, planner(lfirst(ulist))); return (make_append(union_plans, rt_index, rangetable, ((Plan *) lfirst(union_plans))->targetlist)); } break; -#endif case VERSION_FLAG: union_relids = VersionGetParents(rt_entry->relid); @@ -172,34 +203,6 @@ plan_union_queries(Index rt_index, /* do nothing */ break; } - - /* - * Remove the flag for this relation, since we're about to handle it - * (do it before recursing!). XXX destructive parse tree change - */ - switch (flag) - { - case INHERITS_FLAG: - rt_fetch(rt_index, rangetable)->inh = false; - break; - default: - break; - } - - /* - * XXX - can't find any reason to sort union-relids as paul did, so - * we're leaving it out for now (maybe forever) - jeff & lp - * - * [maybe so. btw, jeff & lp did the lisp conversion, according to Paul. - * -- ay 10/94.] - */ - union_plans = plan_union_query(union_relids, rt_index, rt_entry, - parse, flag, &union_rt_entries); - - return (make_append(union_plans, - rt_index, - union_rt_entries, - ((Plan *) lfirst(union_plans))->targetlist)); } diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index 7c553f3625..05a1ecf335 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.55 1997/12/23 19:39:42 thomas Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.56 1997/12/24 06:06:18 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -821,18 +821,7 @@ transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt) /* fix where clause */ qry->qual = transformWhereClause(pstate, stmt->whereClause); - /* check subselect clause */ - if (stmt->unionClause) - { - elog(NOTICE, "UNION not yet supported; using first SELECT only", NULL); - - /* XXX HACK just playing with union clause - thomas 1997-12-19 */ - if ((qry->uniqueFlag == NULL) - && (! ((SubSelect *)lfirst(stmt->unionClause))->unionall)) - qry->uniqueFlag = "*"; - } - - /* check subselect clause */ + /* check having clause */ if (stmt->havingClause) elog(NOTICE, "HAVING not yet supported; ignore clause", NULL); @@ -842,7 +831,6 @@ transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt) qry->targetList, qry->uniqueFlag); - /* fix group by clause */ qry->groupClause = transformGroupClause(pstate, stmt->groupClause, qry->targetList); @@ -851,6 +839,20 @@ transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt) if (pstate->p_numAgg > 0) finalizeAggregates(pstate, qry); + if (stmt->unionClause) + { + List *ulist = NIL; + QueryTreeList *qlist; + int i; + + qlist = parse_analyze(stmt->unionClause); + for (i=0; i < qlist->len; i++) + ulist = lappend(ulist, qlist->qtrees[i]); + qry->unionClause = ulist; + } + else + qry->unionClause = NULL; + return (Query *) qry; } diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y index 58cb72f381..7454c1c2bf 100644 --- a/src/backend/parser/gram.y +++ b/src/backend/parser/gram.y @@ -10,7 +10,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.80 1997/12/23 19:47:32 thomas Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.81 1997/12/24 06:06:26 momjian Exp $ * * HISTORY * AUTHOR DATE MAJOR EVENT @@ -120,11 +120,13 @@ Oid param_type(int t); /* used in parse_expr.c */ ProcedureStmt, RecipeStmt, RemoveAggrStmt, RemoveOperStmt, RemoveFuncStmt, RemoveStmt, RenameStmt, RevokeStmt, RuleStmt, TransactionStmt, ViewStmt, LoadStmt, - CreatedbStmt, DestroydbStmt, VacuumStmt, RetrieveStmt, CursorStmt, - ReplaceStmt, AppendStmt, NotifyStmt, DeleteStmt, ClusterStmt, + CreatedbStmt, DestroydbStmt, VacuumStmt, CursorStmt, SubSelect, + ReplaceStmt, AppendStmt, RetrieveStmt, NotifyStmt, DeleteStmt, ClusterStmt, ExplainStmt, VariableSetStmt, VariableShowStmt, VariableResetStmt, CreateUserStmt, AlterUserStmt, DropUserStmt +%type + %type opt_database, location %type user_createdb_clause, user_createuser_clause @@ -132,7 +134,6 @@ Oid param_type(int t); /* used in parse_expr.c */ %type user_valid_clause %type user_group_list, user_group_clause -%type SubSelect %type join_expr, join_outer, join_spec %type TriggerActionTime, TriggerForSpec, PLangTrusted @@ -1049,19 +1050,10 @@ OptArchiveType: ARCHIVE '=' NONE { } CreateAsStmt: CREATE TABLE relation_name OptCreateAs AS SubSelect { - RetrieveStmt *n = makeNode(RetrieveStmt); - SubSelect *s = (SubSelect *)$6; - n->unique = s->unique; - n->targetList = s->targetList; + RetrieveStmt *n = (RetrieveStmt *)$6; if ($4 != NIL) mapTargetColumns($4, n->targetList); n->into = $3; - n->fromClause = s->fromClause; - n->whereClause = s->whereClause; - n->groupClause = s->groupClause; - n->havingClause = s->havingClause; - n->unionClause = NULL; - n->sortClause = NULL; $$ = (Node *)n; } ; @@ -2291,7 +2283,7 @@ RetrieveStmt: SELECT opt_unique res_target_list2 union_clause: UNION opt_union select_list { - SubSelect *n = lfirst($3); + RetrieveStmt *n = (RetrieveStmt *)lfirst($3); n->unionall = $2; $$ = $3; } @@ -2301,7 +2293,7 @@ union_clause: UNION opt_union select_list select_list: select_list UNION opt_union SubSelect { - SubSelect *n = (SubSelect *)$4; + RetrieveStmt *n = (RetrieveStmt *)$4; n->unionall = $3; $$ = lappend($1, $4); } @@ -2313,7 +2305,7 @@ SubSelect: SELECT opt_unique res_target_list2 from_clause where_clause group_clause having_clause { - SubSelect *n = makeNode(SubSelect); + RetrieveStmt *n = makeNode(RetrieveStmt); n->unique = $2; n->unionall = FALSE; n->targetList = $3; diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h index d2b2066d3a..a6b9a400ea 100644 --- a/src/include/nodes/parsenodes.h +++ b/src/include/nodes/parsenodes.h @@ -6,7 +6,7 @@ * * Copyright (c) 1994, Regents of the University of California * - * $Id: parsenodes.h,v 1.38 1997/12/23 19:58:12 thomas Exp $ + * $Id: parsenodes.h,v 1.39 1997/12/24 06:06:53 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -58,6 +58,8 @@ typedef struct Query int qry_numAgg; /* number of aggregates in the target list */ Aggreg **qry_aggs; /* the aggregates */ + List *unionClause; /* unions are linked under the previous query */ + /* internal to planner */ List *base_relation_list_; /* base relation list */ List *join_relation_list_; /* list of relations */ @@ -634,6 +636,7 @@ typedef struct RetrieveStmt Node *havingClause; /* having conditional-expression */ List *unionClause; /* union subselect parameters */ List *sortClause; /* sort clause (a list of SortGroupBy's) */ + int unionall; /* union without unique sort */ } RetrieveStmt; @@ -641,21 +644,6 @@ typedef struct RetrieveStmt * Supporting data structures for Parse Trees ****************************************************************************/ -/* - * SubSelect - specifies subselect parameters - */ -typedef struct SubSelect -{ - NodeTag type; - char *unique; /* NULL, '*', or unique attribute name */ - int unionall; /* union without unique sort */ - List *targetList; /* the target list (of ResTarget) */ - List *fromClause; /* the from clause */ - Node *whereClause; /* qualifications */ - List *groupClause; /* group by clause */ - Node *havingClause; /* having conditional-expression */ -} SubSelect; - /* * TypeName - specifies a type in definitions */ diff --git a/src/include/optimizer/prep.h b/src/include/optimizer/prep.h index 8f63f798cb..7b22bb5f39 100644 --- a/src/include/optimizer/prep.h +++ b/src/include/optimizer/prep.h @@ -6,7 +6,7 @@ * * Copyright (c) 1994, Regents of the University of California * - * $Id: prep.h,v 1.9 1997/12/20 07:59:44 momjian Exp $ + * $Id: prep.h,v 1.10 1997/12/24 06:06:58 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -32,7 +32,7 @@ extern List *preprocess_targetlist(List *tlist, int command_type, */ typedef enum UnionFlag { - INHERITS_FLAG, VERSION_FLAG + INHERITS_FLAG, UNION_FLAG, VERSION_FLAG } UnionFlag; extern List *find_all_inheritors(List *unexamined_relids,