]> git.ipfire.org Git - thirdparty/postgresql.git/commitdiff
Implementation of UNIONs.
authorBruce Momjian <bruce@momjian.us>
Wed, 24 Dec 1997 06:06:58 +0000 (06:06 +0000)
committerBruce Momjian <bruce@momjian.us>
Wed, 24 Dec 1997 06:06:58 +0000 (06:06 +0000)
src/backend/nodes/copyfuncs.c
src/backend/optimizer/plan/planner.c
src/backend/optimizer/prep/prepunion.c
src/backend/parser/analyze.c
src/backend/parser/gram.y
src/include/nodes/parsenodes.h
src/include/optimizer/prep.h

index f7a88a54b2b2de9731516d03db136effd0210e10..96dc5097e1020dda46a6206800f6f3b0c5261ae5 100644 (file)
@@ -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;
 }
 
index ddfc42891738bc5e42ec71db08f0cad8c55d3133..cc3d9dfd7f83784bcde00eb9186bf0b5992d219f 100644 (file)
@@ -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,
index 11e9489942ed5db2ca950bd6e0e4ca252e5e3f3d..877e4c865412394b5bb2d9dcf6bd0d5d64031c85 100644 (file)
@@ -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));
 }
 
 
index 7c553f3625f9f2d9dcf4643d1629bee844649c02..05a1ecf3352b49ffa2f09ec1696fb4910ea6499b 100644 (file)
@@ -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;
 }
 
index 58cb72f3811bce7a30c7962dfb3d9d17b13bfe40..7454c1c2bf5a7a031d3c6ce568c135ac30243d65 100644 (file)
@@ -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 <rtstmt> 
+
 %type <str>            opt_database, location
 
 %type <pboolean> user_createdb_clause, user_createuser_clause
@@ -132,7 +134,6 @@ Oid param_type(int t); /* used in parse_expr.c */
 %type <str>   user_valid_clause
 %type <list>  user_group_list, user_group_clause
 
-%type <node>   SubSelect
 %type <str>            join_expr, join_outer, join_spec
 %type <boolean> 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;
index d2b2066d3a8dfc4b0a58a1c2930e687b7de59985..a6b9a400ea559a6f98b6e9a706dee13b6bbdc139 100644 (file)
@@ -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
  */
index 8f63f798cb8dafbfc1102ca223571b814ad33174..7b22bb5f39e25a260b342fc500b5dd3425daf4f0 100644 (file)
@@ -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,