Implementation of UNIONs.
authorBruce Momjian
Wed, 24 Dec 1997 06:06:58 +0000 (06:06 +0000)
committerBruce Momjian
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  
+
 %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;
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,