]> git.ipfire.org Git - thirdparty/postgresql.git/commitdiff
Revise union_planner and associated routines to clean up breakage
authorTom Lane <tgl@sss.pgh.pa.us>
Mon, 3 May 1999 00:38:44 +0000 (00:38 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Mon, 3 May 1999 00:38:44 +0000 (00:38 +0000)
from EXCEPT/HAVING patch.  Cases involving nontrivial GROUP BY expressions
now work again.  Also, the code is at least somewhat better documented...

src/backend/optimizer/plan/planmain.c
src/backend/optimizer/plan/planner.c
src/backend/optimizer/plan/setrefs.c
src/backend/optimizer/util/var.c
src/include/optimizer/planmain.h

index 0e0842f357ff2b7ced54c6b10ed945ea022c8acc..0708e963b4b1aff6cabb0c2c8a702cde080074a9 100644 (file)
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.34 1999/02/21 03:48:49 scrappy Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.35 1999/05/03 00:38:43 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -44,9 +44,6 @@
 static Plan *subplanner(Query *root, List *flat_tlist, List *qual);
 static Result *make_result(List *tlist, Node *resconstantqual, Plan *subplan);
 
-extern Plan *make_groupPlan(List **tlist, bool tuplePerGroup,
-                          List *groupClause, Plan *subplan);
-
 /*
  * query_planner
  *       Routine to create a query plan.  It does so by first creating a
@@ -177,18 +174,14 @@ query_planner(Query *root,
         */
        if (constant_qual)
        {
-               subplan = (Plan *) make_result((!root->hasAggs &&
-                                                                               !root->groupClause &&
-                                                                               !root->havingQual)
-                                                                          ? tlist : subplan->targetlist,
+               subplan = (Plan *) make_result(tlist,
                                                                           (Node *) constant_qual,
                                                                           subplan);
 
                /*
-                * Change all varno's of the Result's node target list.
+                * Fix all varno's of the Result's node target list.
                 */
-               if (!root->hasAggs && !root->groupClause && !root->havingQual)
-                       set_tlist_references(subplan);
+               set_tlist_references(subplan);
 
                return subplan;
        }
@@ -201,16 +194,15 @@ query_planner(Query *root,
         * responsibility to optimally push these expressions down the plan
         * tree.  -- Wei
         *
-        * But now nothing to do if there are GroupBy and/or Aggregates: 1.
-        * make_groupPlan fixes tlist; 2. flatten_tlist_vars does nothing with
-        * aggregates fixing only other entries (i.e. - GroupBy-ed and so
-        * fixed by make_groupPlan).     - vadim 04/05/97
+        * Note: formerly there was a test here to skip the flatten call if we
+        * expected union_planner to insert a Group or Agg node above our result.
+        * However, now union_planner tells us exactly what it wants returned,
+        * and we just do it.  Much cleaner.
         */
        else
        {
-               if (!root->hasAggs && !root->groupClause && !root->havingQual)
-                       subplan->targetlist = flatten_tlist_vars(tlist,
-                                                                                                        subplan->targetlist);
+               subplan->targetlist = flatten_tlist_vars(tlist,
+                                                                                                subplan->targetlist);
                return subplan;
        }
 
@@ -321,201 +313,3 @@ make_result(List *tlist,
 
        return node;
 }
-
-/*****************************************************************************
- *
- *****************************************************************************/
-
-Plan *
-make_groupPlan(List **tlist,
-                          bool tuplePerGroup,
-                          List *groupClause,
-                          Plan *subplan)
-{
-       List       *sort_tlist;
-       List       *sl,
-                          *gl;
-       List       *glc = listCopy(groupClause);
-       List       *otles = NIL;        /* list of removed non-GroupBy entries */
-       List       *otlvars = NIL;      /* list of var in them */
-       int                     otlvcnt;
-       Sort       *sortplan;
-       Group      *grpplan;
-       int                     numCols;
-       AttrNumber *grpColIdx;
-       int                     last_resno = 1;
-
-       numCols = length(groupClause);
-       grpColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numCols);
-
-       sort_tlist = new_unsorted_tlist(*tlist);        /* it's copy */
-
-       /*
-        * Make template TL for subplan, Sort & Group: 1. If there are
-        * aggregates (tuplePerGroup is true) then take away non-GroupBy
-        * entries and re-set resno-s accordantly. 2. Make grpColIdx
-        *
-        * Note: we assume that TLEs in *tlist are ordered in accordance with
-        * their resdom->resno.
-        */
-       foreach(sl, sort_tlist)
-       {
-               Resdom     *resdom = NULL;
-               TargetEntry *te = (TargetEntry *) lfirst(sl);
-               int                     keyno = 0;
-
-               foreach(gl, groupClause)
-               {
-                       GroupClause *grpcl = (GroupClause *) lfirst(gl);
-
-                       keyno++;
-                       if (grpcl->entry->resdom->resno == te->resdom->resno)
-                       {
-
-                               resdom = te->resdom;
-                               resdom->reskey = keyno;
-                               resdom->reskeyop = get_opcode(grpcl->grpOpoid);
-                               resdom->resno = last_resno;             /* re-set */
-                               grpColIdx[keyno - 1] = last_resno++;
-                               glc = lremove(lfirst(gl), glc); /* TLE found for it */
-                               break;
-                       }
-               }
-
-               /*
-                * Non-GroupBy entry: remove it from Group/Sort TL if there are
-                * aggregates in query - it will be evaluated by Aggregate plan
-                */
-               if (resdom == NULL)
-               {
-                       if (tuplePerGroup)
-                       {
-                               otlvars = nconc(otlvars, pull_var_clause(te->expr));
-                               otles = lcons(te, otles);
-                               sort_tlist = lremove(te, sort_tlist);
-                       }
-                       else
-                               te->resdom->resno = last_resno++;
-               }
-       }
-
-       if (length(glc) != 0)
-               elog(ERROR, "group attribute disappeared from target list");
-
-       /*
-        * If non-GroupBy entries were removed from TL - we are to add Vars
-        * for them to the end of TL if there are no such Vars in TL already.
-        */
-
-       otlvcnt = length(otlvars);
-       foreach(gl, otlvars)
-       {
-               Var                *v = (Var *) lfirst(gl);
-
-               if (tlist_member(v, sort_tlist) == NULL)
-               {
-                       sort_tlist = lappend(sort_tlist,
-                                                                create_tl_element(v, last_resno));
-                       last_resno++;
-               }
-               else
-/* already in TL */
-                       otlvcnt--;
-       }
-       /* Now otlvcnt is number of Vars added in TL for non-GroupBy entries */
-
-       /* Make TL for subplan: substitute Vars from subplan TL into new TL */
-       sl = flatten_tlist_vars(sort_tlist, subplan->targetlist);
-
-       subplan->targetlist = new_unsorted_tlist(sl);           /* there */
-
-       /*
-        * Make Sort/Group TL : 1. make Var nodes (with varno = 1 and varnoold
-        * = -1) for all functions, 'couse they will be evaluated by subplan;
-        * 2. for real Vars: set varno = 1 and varattno to its resno in
-        * subplan
-        */
-       foreach(sl, sort_tlist)
-       {
-               TargetEntry *te = (TargetEntry *) lfirst(sl);
-               Resdom     *resdom = te->resdom;
-               Node       *expr = te->expr;
-
-               if (IsA(expr, Var))
-               {
-#ifdef NOT_USED                                                        /* subplanVar->resdom->resno expected to
-                                                                * be = te->resdom->resno */
-                       TargetEntry *subplanVar;
-
-                       subplanVar = match_varid((Var *) expr, subplan->targetlist);
-                       ((Var *) expr)->varattno = subplanVar->resdom->resno;
-#endif
-                       ((Var *) expr)->varattno = te->resdom->resno;
-                       ((Var *) expr)->varno = 1;
-               }
-               else
-                       te->expr = (Node *) makeVar(1, resdom->resno,
-                                                                               resdom->restype,
-                                                                               resdom->restypmod,
-                                                                               0, -1, resdom->resno);
-       }
-
-       sortplan = make_sort(sort_tlist,
-                                                _NONAME_RELATION_ID_,
-                                                subplan,
-                                                numCols);
-       sortplan->plan.cost = subplan->cost;            /* XXX assume no cost */
-
-       /*
-        * make the Group node
-        */
-       sort_tlist = copyObject(sort_tlist);
-       grpplan = make_group(sort_tlist, tuplePerGroup, numCols,
-                                                grpColIdx, sortplan);
-
-       /*
-        * Make TL for parent: "restore" non-GroupBy entries (if they were
-        * removed) and set resno-s of others accordantly.
-        */
-       sl = sort_tlist;
-       sort_tlist = NIL;                       /* to be new parent TL */
-       foreach(gl, *tlist)
-       {
-               List       *temp = NIL;
-               TargetEntry *te = (TargetEntry *) lfirst(gl);
-
-               foreach(temp, otles)    /* Is it removed non-GroupBy entry ? */
-               {
-                       TargetEntry *ote = (TargetEntry *) lfirst(temp);
-
-                       if (ote->resdom->resno == te->resdom->resno)
-                       {
-                               otles = lremove(ote, otles);
-                               break;
-                       }
-               }
-               if (temp == NIL)                /* It's "our" TLE - we're to return */
-               {                                               /* it from Sort/Group plans */
-                       TargetEntry *my = (TargetEntry *) lfirst(sl);           /* get it */
-
-                       sl = sl->next;          /* prepare for the next "our" */
-                       my = copyObject(my);
-                       my->resdom->resno = te->resdom->resno;          /* order of parent TL */
-                       sort_tlist = lappend(sort_tlist, my);
-                       continue;
-               }
-               /* else - it's TLE of an non-GroupBy entry */
-               sort_tlist = lappend(sort_tlist, copyObject(te));
-       }
-
-       /*
-        * Pure non-GroupBy entries Vars were at the end of Group' TL. They
-        * shouldn't appear in parent TL, all others shouldn't disappear.
-        */
-       Assert(otlvcnt == length(sl));
-       Assert(length(otles) == 0);
-
-       *tlist = sort_tlist;
-
-       return (Plan *) grpplan;
-}
index 543b5d6d7c6aaa8e971191e4704340b68f6f7e59..aeaa07658cc5aa3539d60039d2ab366e1e7099fc 100644 (file)
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.47 1999/04/19 01:43:11 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.48 1999/05/03 00:38:43 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "access/genam.h"
 #include "parser/parse_oper.h"
 
+static List *make_subplanTargetList(Query *parse, List *tlist,
+                                                                       AttrNumber **groupColIdx);
+static Plan *make_groupplan(List *group_tlist, bool tuplePerGroup,
+                                                       List *groupClause, AttrNumber *grpColIdx,
+                                                       Plan *subplan);
 static bool need_sortplan(List *sortcls, Plan *plan);
 static Plan *make_sortplan(List *tlist, List *sortcls, Plan *plannode);
-extern Plan *make_groupPlan(List **tlist, bool tuplePerGroup,
-                          List *groupClause, Plan *subplan);
 
 /*****************************************************************************
  *
@@ -103,16 +106,9 @@ Plan *
 union_planner(Query *parse)
 {
        List       *tlist = parse->targetList;
-
-       /***S*H***/
-       /* copy the original tlist, we will need the original one 
-        * for the AGG node later on */
-       List    *new_tlist = new_unsorted_tlist(tlist);
-               
        List       *rangetable = parse->rtable;
-
        Plan       *result_plan = (Plan *) NULL;
-
+       AttrNumber *groupColIdx = NULL;
        Index           rt_index;
 
        if (parse->unionClause)
@@ -138,36 +134,35 @@ union_planner(Query *parse)
        else
        {
          List  **vpm = NULL;
+         List  *sub_tlist;
 
-         /*
-          * If there is a HAVING clause, make sure all vars referenced in it
-          * are included in the target list for query_planner().
-          */
-         if (parse->havingQual)
-                 new_tlist = check_having_qual_for_vars(parse->havingQual, new_tlist);
-
-         new_tlist = preprocess_targetlist(new_tlist,
-                                           parse->commandType,
-                                           parse->resultRelation,
-                                           parse->rtable);
+         /* Preprocess targetlist in case we are inside an INSERT/UPDATE. */
+         tlist = preprocess_targetlist(tlist,
+                                                                       parse->commandType,
+                                                                       parse->resultRelation,
+                                                                       parse->rtable);
 
-         /* FOR UPDATE ... */
+         /* Add row-mark targets for UPDATE
+          * (should this be done in preprocess_targetlist?)
+          */
          if (parse->rowMark != NULL)
          {
                List               *l;
-               TargetEntry        *ctid;
-               Resdom             *resdom;
-               Var                        *var;
-               char               *resname;
 
                foreach (l, parse->rowMark)
                {
-                       if (!(((RowMark*)lfirst(l))->info & ROW_MARK_FOR_UPDATE))
+                       RowMark            *rowmark = (RowMark*) lfirst(l);
+                       TargetEntry        *ctid;
+                       Resdom             *resdom;
+                       Var                        *var;
+                       char               *resname;
+
+                       if (!(rowmark->info & ROW_MARK_FOR_UPDATE))
                                continue;
 
                        resname = (char*) palloc(32);
-                       sprintf(resname, "ctid%u", ((RowMark*)lfirst(l))->rti);
-                       resdom = makeResdom(length(new_tlist) + 1,
+                       sprintf(resname, "ctid%u", rowmark->rti);
+                       resdom = makeResdom(length(tlist) + 1,
                                                                TIDOID,
                                                                -1,
                                                                resname,
@@ -175,20 +170,20 @@ union_planner(Query *parse)
                                                                0,
                                                                1);
 
-                       var = makeVar(((RowMark*)lfirst(l))->rti, -1, TIDOID, 
-                                                       -1, 0, ((RowMark*)lfirst(l))->rti, -1);
+                       var = makeVar(rowmark->rti, -1, TIDOID, 
+                                                 -1, 0, rowmark->rti, -1);
 
                        ctid = makeTargetEntry(resdom, (Node *) var);
-                       new_tlist = lappend(new_tlist, ctid);
+                       tlist = lappend(tlist, ctid);
                }
          }
-         
-         /* Here starts the original (pre having) code */
-         tlist = preprocess_targetlist(tlist,
-                                       parse->commandType,
-                                       parse->resultRelation,
-                                       parse->rtable);
-         
+
+         /* Generate appropriate target list for subplan; may be different
+          * from tlist if grouping or aggregation is needed.
+          */
+         sub_tlist = make_subplanTargetList(parse, tlist, &groupColIdx);
+
+         /* Generate the (sub) plan */
          if (parse->rtable != NULL)
          {
              vpm = (List **) palloc(length(parse->rtable) * sizeof(List *));
@@ -196,9 +191,9 @@ union_planner(Query *parse)
          }
          PlannerVarParam = lcons(vpm, PlannerVarParam);
          result_plan = query_planner(parse,
-                                     parse->commandType,
-                                     new_tlist,
-                                     (List *) parse->qual);
+                                                                 parse->commandType,
+                                                                 sub_tlist,
+                                                                 (List *) parse->qual);
          PlannerVarParam = lnext(PlannerVarParam);
          if (vpm != NULL)
            pfree(vpm);          
@@ -211,21 +206,28 @@ union_planner(Query *parse)
        if (parse->groupClause)
        {
                bool            tuplePerGroup;
+               List       *group_tlist;
 
                /*
-                * decide whether how many tuples per group the Group node needs
+                * Decide whether how many tuples per group the Group node needs
                 * to return. (Needs only one tuple per group if no aggregate is
                 * present. Otherwise, need every tuple from the group to do the
-                * aggregation.)
+                * aggregation.)  Note tuplePerGroup is named backwards :-(
                 */
                tuplePerGroup = parse->hasAggs;
 
-               /***S*H***/
-               /* Use 'new_tlist' instead of 'tlist' */
-               result_plan = make_groupPlan(&new_tlist,
-                                                                  tuplePerGroup,
-                                                                  parse->groupClause,
-                                                                  result_plan);
+               /* If there are aggregates then the Group node should just return
+                * the same (simplified) tlist as the subplan, which we indicate
+                * to make_groupplan by passing NIL.  If there are no aggregates
+                * then the Group node had better compute the final tlist.
+                */
+               group_tlist = parse->hasAggs ? NIL : tlist;
+
+               result_plan = make_groupplan(group_tlist,
+                                                                        tuplePerGroup,
+                                                                        parse->groupClause,
+                                                                        groupColIdx,
+                                                                        result_plan);
        }
 
        /*
@@ -274,10 +276,6 @@ union_planner(Query *parse)
         */
        if (parse->hasAggs)
        {
-               /* Use 'tlist' not 'new_tlist' as target list because we
-                * don't want the additional attributes used for the havingQual
-                * (see above) to show up in the result
-                */
                result_plan = (Plan *) make_agg(tlist, result_plan);
 
                /* HAVING clause, if any, becomes qual of the Agg node */
@@ -289,6 +287,16 @@ union_planner(Query *parse)
                 */
                if (! set_agg_tlist_references((Agg *) result_plan))
                        elog(ERROR, "SELECT/HAVING requires aggregates to be valid");
+
+               /*
+                * Check that we actually found some aggregates, else executor
+                * will die unpleasantly.  (The rewrite module currently has bugs
+                * that allow hasAggs to be incorrectly set 'true' sometimes.
+                * It's not easy to recover here, since we've already made decisions
+                * assuming there will be an Agg node.)
+                */
+               if (((Agg *) result_plan)->aggs == NIL)
+                       elog(ERROR, "union_planner: query is marked hasAggs, but I don't see any");
        }                 
 
        /*
@@ -316,6 +324,276 @@ union_planner(Query *parse)
 
 }
 
+/*---------------
+ * make_subplanTargetList
+ *       Generate appropriate target lists when grouping is required.
+ *
+ * When union_planner inserts Aggregate and/or Group/Sort plan nodes above
+ * the result of query_planner, we typically need to pass a different
+ * target list to query_planner than the outer plan nodes should have.
+ * This routine generates the correct target list for the subplan, and
+ * if necessary modifies the target list for the inserted nodes as well.
+ *
+ * The initial target list passed from the parser already contains entries
+ * for all ORDER BY and GROUP BY expressions, but it will not have entries
+ * for variables used only in HAVING clauses; so we need to add those
+ * variables to the subplan target list.  Also, if we are doing either
+ * grouping or aggregation, we flatten all expressions except GROUP BY items
+ * into their component variables; the other expressions will be computed by
+ * the inserted nodes rather than by the subplan.  For example,
+ * given a query like
+ *             SELECT a+b,SUM(c+d) FROM table GROUP BY a+b;
+ * we want to pass this targetlist to the subplan:
+ *             a+b,c,d
+ * where the a+b target will be used by the Sort/Group steps, and the
+ * c and d targets will be needed to compute the aggregate results.
+ *
+ * 'parse' is the query being processed.
+ * 'tlist' is the query's target list.  CAUTION: list elements may be
+ * modified by this routine!
+ * 'groupColIdx' receives an array of column numbers for the GROUP BY
+ * expressions (if there are any) in the subplan's target list.
+ *
+ * The result is the targetlist to be passed to the subplan.  Also,
+ * the parent tlist is modified so that any nontrivial targetlist items that
+ * exactly match GROUP BY items are replaced by simple Var nodes referencing
+ * those outputs of the subplan.  This avoids redundant recalculations in
+ * cases like
+ *             SELECT a+1, ... GROUP BY a+1
+ * Note, however, that other varnodes in the parent's targetlist (and
+ * havingQual, if any) will still need to be updated to refer to outputs
+ * of the subplan.  This routine is quite large enough already, so we do
+ * that later.
+ *---------------
+ */
+static List *
+make_subplanTargetList(Query *parse,
+                                          List *tlist,
+                                          AttrNumber **groupColIdx)
+{
+       List       *sub_tlist;
+       List       *prnt_tlist;
+       List       *sl,
+                          *gl;
+       List       *glc = NIL;
+       List       *extravars = NIL;
+       int                     numCols;
+       AttrNumber *grpColIdx = NULL;
+       int                     next_resno = 1;
+
+       *groupColIdx = NULL;
+
+       /* If we're not grouping or aggregating, nothing to do here;
+        * query_planner should receive the unmodified target list.
+        */
+       if (!parse->hasAggs && !parse->groupClause && !parse->havingQual)
+               return tlist;
+
+       /* If grouping, make a working copy of groupClause list (which we use
+        * just to verify that we found all the groupClause items in tlist).
+        * Also allocate space to remember where the group columns are in the
+        * subplan tlist.
+        */
+       numCols = length(parse->groupClause);
+       if (numCols > 0)
+       {
+               glc = listCopy(parse->groupClause);
+               grpColIdx = (AttrNumber *) palloc(sizeof(AttrNumber) * numCols);
+               *groupColIdx = grpColIdx;
+       }
+
+       sub_tlist = new_unsorted_tlist(tlist);  /* make a modifiable copy */
+
+       /*
+        * Step 1: build grpColIdx by finding targetlist items that match
+        * GroupBy entries.  If there are aggregates, remove non-GroupBy items
+        * from sub_tlist, and reset its resnos accordingly.  When we leave an
+        * expression in the subplan tlist, modify the parent tlist to copy the
+        * value from the subplan output rather than re-evaluating it.
+        */
+       prnt_tlist = tlist;                     /* scans parent tlist in sync with sl */
+       foreach(sl, sub_tlist)
+       {
+               TargetEntry *te = (TargetEntry *) lfirst(sl);
+               TargetEntry *parentte = (TargetEntry *) lfirst(prnt_tlist);
+               Resdom     *resdom = te->resdom;
+               bool            keepInSubPlan = true;
+               bool            foundGroupClause = false;
+               int                     keyno = 0;
+
+               foreach(gl, parse->groupClause)
+               {
+                       GroupClause *grpcl = (GroupClause *) lfirst(gl);
+
+                       keyno++;                        /* sort key # for this GroupClause */
+                       /* Is it safe to use just resno to match tlist and glist items?? */
+                       if (grpcl->entry->resdom->resno == resdom->resno)
+                       {
+                               /* Found a matching groupclause; record info for sorting */
+                               foundGroupClause = true;
+                               resdom->reskey = keyno;
+                               resdom->reskeyop = get_opcode(grpcl->grpOpoid);
+                               grpColIdx[keyno - 1] = next_resno;
+                               /* Remove groupclause from our list of unmatched groupclauses.
+                                * NB: this depends on having used a shallow listCopy() above.
+                                */
+                               glc = lremove((void*) grpcl, glc);
+                               break;
+                       }
+               }
+
+               if (! foundGroupClause)
+               {
+                       /*
+                        * Non-GroupBy entry: remove it from subplan if there are
+                        * aggregates in query - it will be evaluated by Aggregate plan.
+                        * But do not remove simple-Var entries; we'd just have to add
+                        * them back anyway, and we risk confusing INSERT/UPDATE.
+                        */
+                       if (parse->hasAggs && ! IsA(te->expr, Var))
+                               keepInSubPlan = false;
+               }
+
+               if (keepInSubPlan)
+               {
+                       /* Assign new sequential resnos to subplan tlist items */
+                       resdom->resno = next_resno++;
+                       if (! IsA(parentte->expr, Var))
+                       {
+                               /* Since the item is being computed in the subplan,
+                                * we can just make a Var node to reference it in the
+                                * outer plan, rather than recomputing it there.
+                                * Note we use varnoold = -1 as a flag to let
+                                * replace_vars_with_subplan_refs know it needn't change
+                                * this Var node.
+                                * If it's only a Var anyway, we leave it alone for now;
+                                * replace_vars_with_subplan_refs will fix it later.
+                                */
+                               parentte->expr = (Node *) makeVar(1, resdom->resno,
+                                                                                                 resdom->restype,
+                                                                                                 resdom->restypmod,
+                                                                                                 0, -1, resdom->resno);
+                       }
+               }
+               else
+               {
+                       /* Remove this tlist item from the subplan, but remember the
+                        * vars it needs.  The outer tlist item probably needs changes,
+                        * but that will happen later.
+                        */
+                       sub_tlist = lremove(te, sub_tlist);
+                       extravars = nconc(extravars, pull_var_clause(te->expr));
+               }
+
+               prnt_tlist = lnext(prnt_tlist);
+       }
+
+       /* We should have found all the GROUP BY clauses in the tlist. */
+       if (length(glc) != 0)
+               elog(ERROR, "make_subplanTargetList: GROUP BY attribute not found in target list");
+
+       /*
+        * Add subplan targets for any variables needed by removed tlist entries
+        * that aren't otherwise mentioned in the subplan target list.
+        * We'll also need targets for any variables seen only in HAVING.
+        */
+       extravars = nconc(extravars, pull_var_clause(parse->havingQual));
+
+       foreach(gl, extravars)
+       {
+               Var                *v = (Var *) lfirst(gl);
+
+               if (tlist_member(v, sub_tlist) == NULL)
+               {
+                       sub_tlist = lappend(sub_tlist,
+                                                               create_tl_element(v, next_resno));
+                       next_resno++;
+               }
+       }
+
+       return sub_tlist;
+}
+
+static Plan *
+make_groupplan(List *group_tlist,
+                          bool tuplePerGroup,
+                          List *groupClause,
+                          AttrNumber *grpColIdx,
+                          Plan *subplan)
+{
+       List       *sort_tlist;
+       List       *sl;
+       Sort       *sortplan;
+       Group      *grpplan;
+       int                     numCols = length(groupClause);
+
+       /*
+        * Make the targetlist for the Sort node; it always just references
+        * each of the corresponding target items of the subplan.  We need to
+        * ensure that simple Vars in the subplan's target list are recognizable
+        * by replace_vars_with_subplan_refs when it's applied to the Sort/Group
+        * target list, so copy up their varnoold/varoattno.
+        */
+       sort_tlist = NIL;
+       foreach(sl, subplan->targetlist)
+       {
+               TargetEntry *te = (TargetEntry *) lfirst(sl);
+               Resdom     *resdom = te->resdom;
+               Var                *newvar;
+
+               if (IsA(te->expr, Var))
+               {
+                       Var        *subvar = (Var *) te->expr;
+                       newvar = makeVar(1, resdom->resno,
+                                                        resdom->restype, resdom->restypmod,
+                                                        0, subvar->varnoold, subvar->varoattno);
+               }
+               else
+               {
+                       newvar = makeVar(1, resdom->resno,
+                                                        resdom->restype, resdom->restypmod,
+                                                        0, -1, resdom->resno);
+               }
+
+               sort_tlist = lappend(sort_tlist,
+                                                        makeTargetEntry((Resdom *) copyObject(resdom),
+                                                                                        (Node *) newvar));
+       }
+
+       /*
+        * Make the Sort node
+        */
+       sortplan = make_sort(sort_tlist,
+                                                _NONAME_RELATION_ID_,
+                                                subplan,
+                                                numCols);
+       sortplan->plan.cost = subplan->cost;            /* XXX assume no cost */
+
+       /*
+        * If the caller gave us a target list, use it after fixing the variables.
+        * If not, we need the same sort of "repeater" tlist as for the Sort node.
+        */
+       if (group_tlist)
+       {
+               group_tlist = copyObject(group_tlist); /* necessary?? */
+               replace_tlist_with_subplan_refs(group_tlist,
+                                                                               (Index) 0,
+                                                                               subplan->targetlist);
+       }
+       else
+       {
+               group_tlist = copyObject(sort_tlist);
+       }
+
+       /*
+        * Make the Group node
+        */
+       grpplan = make_group(group_tlist, tuplePerGroup, numCols,
+                                                grpColIdx, sortplan);
+
+       return (Plan *) grpplan;
+}
+
 /*
  * make_sortplan
  *       Returns a sortplan which is basically a SORT node attached to the
@@ -384,6 +662,8 @@ make_sortplan(List *tlist, List *sortcls, Plan *plannode)
  * the final query in the function.  We do some ad-hoc define-time
  * type checking here to be sure that the user is returning the
  * type he claims.
+ *
+ * XXX Why is this function in this module?
  */
 void
 pg_checkretval(Oid rettype, QueryTreeList *queryTreeList)
index b7b8d89c5a7c1813cba161413bbbc22a75be9e9b..4506097af9f598ac3f88afc95660831a11cfbe37 100644 (file)
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.43 1999/04/29 00:20:27 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.44 1999/05/03 00:38:43 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -42,9 +42,8 @@ static List *replace_subclause_joinvar_refs(List *clauses,
                                                           List *outer_tlist, List *inner_tlist);
 static Var *replace_joinvar_refs(Var *var, List *outer_tlist, List *inner_tlist);
 static List *tlist_noname_references(Oid nonameid, List *tlist);
-static void replace_result_clause(Node *clause, List *subplanTargetList);
 static bool OperandIsInner(Node *opnd, int inner_relid);
-static List *replace_agg_clause(Node *expr, List *targetlist);
+static List *pull_agg_clause(Node *clause);
 static Node *del_agg_clause(Node *clause);
 static void set_result_tlist_references(Result *resultNode);
 
@@ -542,9 +541,6 @@ set_result_tlist_references(Result *resultNode)
        Plan       *subplan;
        List       *resultTargetList;
        List       *subplanTargetList;
-       List       *t;
-       TargetEntry *entry;
-       Expr       *expr;
 
        resultTargetList = ((Plan *) resultNode)->targetlist;
 
@@ -558,33 +554,51 @@ set_result_tlist_references(Result *resultNode)
        else
                subplanTargetList = NIL;
 
-       /*
-        * now for traverse all the entris of the target list. These should be
-        * of the form (Resdom_Node Expression). For every expression clause,
-        * call "replace_result_clause()" to appropriatelly change all the Var
-        * nodes.
-        */
-       foreach(t, resultTargetList)
+       replace_tlist_with_subplan_refs(resultTargetList,
+                                                                       (Index) OUTER,
+                                                                       subplanTargetList);
+}
+
+/*---------------------------------------------------------
+ *
+ * replace_tlist_with_subplan_refs
+ *
+ * Applies replace_vars_with_subplan_refs() to each entry of a targetlist.
+ */
+void
+replace_tlist_with_subplan_refs(List *tlist,
+                                                               Index subvarno,
+                                                               List *subplanTargetList)
+{
+       List   *t;
+
+       foreach(t, tlist)
        {
-               entry = (TargetEntry *) lfirst(t);
-               expr = (Expr *) get_expr(entry);
-               replace_result_clause((Node *) expr, subplanTargetList);
+               TargetEntry *entry = (TargetEntry *) lfirst(t);
+               replace_vars_with_subplan_refs((Node *) get_expr(entry),
+                                                                          subvarno, subplanTargetList);
        }
 }
 
 /*---------------------------------------------------------
  *
- * replace_result_clause
+ * replace_vars_with_subplan_refs
+ *
+ * This routine modifies (destructively!) an expression tree so that all
+ * Var nodes reference target nodes of a subplan.  It is used to fix up
+ * target expressions of upper-level plan nodes.
  *
- * This routine is called from set_result_tlist_references().
- * and modifies the expressions of the target list of a Result
- * node so that all Var nodes reference the target list of its subplan.
+ * 'clause': the tree to be fixed
+ * 'subvarno': varno to be assigned to all Vars
+ * 'subplanTargetList': target list for subplan
  *
+ * Afterwards, all Var nodes have varno = subvarno, varattno = resno
+ * of corresponding subplan target.
  */
-static void
-replace_result_clause(Node *clause,
-                                         List *subplanTargetList)      /* target list of the
-                                                                                                * subplan */
+void
+replace_vars_with_subplan_refs(Node *clause,
+                                                          Index subvarno,
+                                                          List *subplanTargetList)
 {
        List       *t;
 
@@ -592,82 +606,100 @@ replace_result_clause(Node *clause,
                return;
        if (IsA(clause, Var))
        {
-               TargetEntry *subplanVar;
-
                /*
                 * Ha! A Var node!
+                *
+                * It could be that this varnode has been created by make_groupplan
+                * and is already set up to reference the subplan target list.
+                * We recognize that case by varno = 1, varnoold = -1,
+                * varattno = varoattno, and varlevelsup = 0.  (Probably ought to
+                * have an explicit flag, but this should do for now.)
                 */
-               subplanVar = match_varid((Var *) clause, subplanTargetList);
+               Var                     *var = (Var *) clause;
+               TargetEntry *subplanVar;
+
+               if (var->varno == (Index) 1 && 
+                       var->varnoold == ((Index) -1) &&
+                       var->varattno == var->varoattno &&
+                       var->varlevelsup == 0)
+                       return;                         /* OK to leave it alone */
 
+               /* Otherwise it had better be in the subplan list. */
+               subplanVar = match_varid(var, subplanTargetList);
                if (! subplanVar)
-                       elog(ERROR, "replace_result_clause: variable not in target list");
+                       elog(ERROR, "replace_vars_with_subplan_refs: variable not in target list");
 
                /*
                 * Change the varno & varattno fields of the var node.
                 */
-               ((Var *) clause)->varno = (Index) OUTER;
-               ((Var *) clause)->varattno = subplanVar->resdom->resno;
+               var->varno = subvarno;
+               var->varattno = subplanVar->resdom->resno;
        }
-       else if (IsA(clause, Aggref))
-               replace_result_clause(((Aggref *) clause)->target, subplanTargetList);
-       else if (is_funcclause(clause))
+       else if (single_node(clause))
+       {
+               /* do nothing! */
+       }
+       else if (IsA(clause, Iter))
+               replace_vars_with_subplan_refs(((Iter *) clause)->iterexpr,
+                                                                          subvarno, subplanTargetList);
+       else if (is_subplan(clause))
+       {
+               foreach(t, ((Expr *) clause)->args)
+                       replace_vars_with_subplan_refs(lfirst(t),
+                                                                                  subvarno, subplanTargetList);
+               foreach(t, ((SubPlan *) ((Expr *) clause)->oper)->sublink->oper)
+                       replace_vars_with_subplan_refs(lfirst(((Expr *) lfirst(t))->args),
+                                                                                  subvarno, subplanTargetList);
+       }
+       else if (IsA(clause, Expr))
        {
-               List       *subExpr;
-
                /*
-                * This is a function. Recursively call this routine for its
-                * arguments...
+                * Recursively scan the arguments of an expression.
+                * NOTE: this must come after is_subplan() case since
+                * subplan is a kind of Expr node.
                 */
-               subExpr = ((Expr *) clause)->args;
-               foreach(t, subExpr)
-                       replace_result_clause(lfirst(t), subplanTargetList);
+               foreach(t, ((Expr *) clause)->args)
+                       replace_vars_with_subplan_refs(lfirst(t),
+                                                                                  subvarno, subplanTargetList);
        }
+       else if (IsA(clause, Aggref))
+               replace_vars_with_subplan_refs(((Aggref *) clause)->target,
+                                                                          subvarno, subplanTargetList);
        else if (IsA(clause, ArrayRef))
        {
                ArrayRef   *aref = (ArrayRef *) clause;
-
-               /*
-                * This is an arrayref. Recursively call this routine for its
-                * expression and its index expression...
-                */
                foreach(t, aref->refupperindexpr)
-                       replace_result_clause(lfirst(t), subplanTargetList);
+                       replace_vars_with_subplan_refs(lfirst(t),
+                                                                                  subvarno, subplanTargetList);
                foreach(t, aref->reflowerindexpr)
-                       replace_result_clause(lfirst(t), subplanTargetList);
-               replace_result_clause(aref->refexpr,
-                                                         subplanTargetList);
-               replace_result_clause(aref->refassgnexpr,
-                                                         subplanTargetList);
+                       replace_vars_with_subplan_refs(lfirst(t),
+                                                                                  subvarno, subplanTargetList);
+               replace_vars_with_subplan_refs(aref->refexpr,
+                                                                          subvarno, subplanTargetList);
+               replace_vars_with_subplan_refs(aref->refassgnexpr,
+                                                                          subvarno, subplanTargetList);
        }
-       else if (is_opclause(clause))
+       else if (case_clause(clause))
        {
-               Node       *subNode;
-
-               /*
-                * This is an operator. Recursively call this routine for both its
-                * left and right operands
-                */
-               subNode = (Node *) get_leftop((Expr *) clause);
-               replace_result_clause(subNode, subplanTargetList);
-               subNode = (Node *) get_rightop((Expr *) clause);
-               replace_result_clause(subNode, subplanTargetList);
-       }
-       else if (IsA(clause, Param) ||IsA(clause, Const))
-       {
-               /* do nothing! */
+               foreach(t, ((CaseExpr *) clause)->args)
+               {
+                       CaseWhen   *when = (CaseWhen *) lfirst(t);
+                       replace_vars_with_subplan_refs(when->expr,
+                                                                                  subvarno, subplanTargetList);
+                       replace_vars_with_subplan_refs(when->result,
+                                                                                  subvarno, subplanTargetList);
+               }
+               replace_vars_with_subplan_refs(((CaseExpr *) clause)->defresult,
+                                                                          subvarno, subplanTargetList);
        }
        else
        {
-
-               /*
-                * Ooops! we can not handle that!
-                */
-               elog(ERROR, "replace_result_clause: Can not handle this tlist!\n");
+               elog(ERROR, "replace_vars_with_subplan_refs: Cannot handle node type %d",
+                        nodeTag(clause));
        }
 }
 
-static
-bool
+static bool
 OperandIsInner(Node *opnd, int inner_relid)
 {
 
@@ -723,15 +755,22 @@ set_agg_tlist_references(Agg *aggNode)
        {
                TargetEntry *tle = lfirst(tl);
 
-               aggNode->aggs = nconc(replace_agg_clause(tle->expr, subplanTargetList),
-                                                         aggNode->aggs);
+               replace_vars_with_subplan_refs(tle->expr,
+                                                                          (Index) 0,
+                                                                          subplanTargetList);
+               aggNode->aggs = nconc(pull_agg_clause(tle->expr), aggNode->aggs);
        }
 
        all_quals_ok = true;
        foreach(ql, aggNode->plan.qual)
        {
                Node *qual = lfirst(ql);
-               List *qualaggs = replace_agg_clause(qual, subplanTargetList);
+               List *qualaggs;
+
+               replace_vars_with_subplan_refs(qual,
+                                                                          (Index) 0,
+                                                                          subplanTargetList);
+               qualaggs = pull_agg_clause(qual);
                if (qualaggs == NIL)
                        all_quals_ok = false; /* this qual clause has no agg functions! */
                else
@@ -741,34 +780,21 @@ set_agg_tlist_references(Agg *aggNode)
        return all_quals_ok;
 }
 
+/*
+ * Make a list of all Aggref nodes contained in the given expression.
+ */
 static List *
-replace_agg_clause(Node *clause, List *subplanTargetList)
+pull_agg_clause(Node *clause)
 {
-       List       *t;
        List       *agg_list = NIL;
+       List       *t;
 
        if (clause == NULL)
                return NIL;
-
-       if (IsA(clause, Var))
-       {
-               TargetEntry *subplanVar;
-
-               /*
-                * Ha! A Var node!
-                */
-               subplanVar = match_varid((Var *) clause, subplanTargetList);
-
-               if (! subplanVar)
-                       elog(ERROR, "replace_agg_clause: variable not in target list");
-
-               /*
-                * Change the varno & varattno fields of the var node.
-                */
-               ((Var *) clause)->varattno = subplanVar->resdom->resno;
-
+       else if (single_node(clause))
                return NIL;
-       }
+       else if (IsA(clause, Iter))
+               return pull_agg_clause(((Iter *) clause)->iterexpr);
        else if (is_subplan(clause))
        {
                SubLink *sublink = ((SubPlan *) ((Expr *) clause)->oper)->sublink;
@@ -778,13 +804,10 @@ replace_agg_clause(Node *clause, List *subplanTargetList)
                 * aggregates to be attached to the aggs list
                 */
                foreach(t, sublink->lefthand)
-                       agg_list = nconc(replace_agg_clause(lfirst(t), subplanTargetList),
-                                                        agg_list);
+                       agg_list = nconc(pull_agg_clause(lfirst(t)), agg_list);
                /* The first argument of ...->oper has also to be checked */
                foreach(t, sublink->oper)
-                       agg_list = nconc(replace_agg_clause(lfirst(t), subplanTargetList),
-                                                        agg_list);
-               return agg_list;
+                       agg_list = nconc(pull_agg_clause(lfirst(t)), agg_list);
        }
        else if (IsA(clause, Expr))
        {
@@ -794,53 +817,41 @@ replace_agg_clause(Node *clause, List *subplanTargetList)
                 * subplan is a kind of Expr node.
                 */
                foreach(t, ((Expr *) clause)->args)
-               {
-                       agg_list = nconc(replace_agg_clause(lfirst(t), subplanTargetList),
-                                                        agg_list);
-               }
-               return agg_list;
+                       agg_list = nconc(pull_agg_clause(lfirst(t)), agg_list);
        }
        else if (IsA(clause, Aggref))
        {
                return lcons(clause,
-                                        replace_agg_clause(((Aggref *) clause)->target,
-                                                                               subplanTargetList));
+                                        pull_agg_clause(((Aggref *) clause)->target));
        }
        else if (IsA(clause, ArrayRef))
        {
                ArrayRef   *aref = (ArrayRef *) clause;
-
-               /*
-                * This is an arrayref. Recursively call this routine for its
-                * expression and its index expression...
-                */
                foreach(t, aref->refupperindexpr)
-                       agg_list = nconc(replace_agg_clause(lfirst(t), subplanTargetList),
-                                                        agg_list);
+                       agg_list = nconc(pull_agg_clause(lfirst(t)), agg_list);
                foreach(t, aref->reflowerindexpr)
-                       agg_list = nconc(replace_agg_clause(lfirst(t), subplanTargetList),
-                                                        agg_list);
-               agg_list = nconc(replace_agg_clause(aref->refexpr, subplanTargetList),
-                                                agg_list);
-               agg_list = nconc(replace_agg_clause(aref->refassgnexpr,
-                                                                                       subplanTargetList),
-                                                agg_list);
-               return agg_list;
+                       agg_list = nconc(pull_agg_clause(lfirst(t)), agg_list);
+               agg_list = nconc(pull_agg_clause(aref->refexpr), agg_list);
+               agg_list = nconc(pull_agg_clause(aref->refassgnexpr), agg_list);
        }
-       else if (IsA(clause, Param) || IsA(clause, Const))
+       else if (case_clause(clause))
        {
-               /* do nothing! */
-               return NIL;
+               foreach(t, ((CaseExpr *) clause)->args)
+               {
+                       CaseWhen   *when = (CaseWhen *) lfirst(t);
+                       agg_list = nconc(agg_list, pull_agg_clause(when->expr));
+                       agg_list = nconc(agg_list, pull_agg_clause(when->result));
+               }
+               agg_list = nconc(pull_agg_clause(((CaseExpr *) clause)->defresult),
+                                                agg_list);
        }
        else
        {
-               /*
-                * Ooops! we can not handle that!
-                */
-               elog(ERROR, "replace_agg_clause: Cannot handle node type %d",
+               elog(ERROR, "pull_agg_clause: Cannot handle node type %d",
                         nodeTag(clause));
-               return NIL;
        }
+
+       return agg_list;
 }
 
 
@@ -932,99 +943,6 @@ del_agg_clause(Node *clause)
        return NULL;
 }
 
-/*
- * check_having_qual_for_vars takes the havingQual and the actual targetlist
- * as arguments and recursively scans the havingQual for attributes that are
- * not included in the targetlist yet.  This will occur with queries like:
- *
- * SELECT sid FROM part GROUP BY sid HAVING MIN(pid) > 1;
- *
- * To be able to handle queries like that correctly we have to extend the
- * actual targetlist (which will be the one used for the GROUP node later on)
- * by these attributes.  The return value is the extended targetlist.
- */
-List *
-check_having_qual_for_vars(Node *clause, List *targetlist_so_far)
-{
-       List       *t;
-
-       if (clause == NULL)
-               return targetlist_so_far;
-
-       if (IsA(clause, Var))
-       {
-               RelOptInfo      tmp_rel;
-
-               /*
-                * Ha! A Var node!
-                */
-
-               tmp_rel.targetlist = targetlist_so_far;
-
-               /* Check if the VAR is already contained in the targetlist */
-               if (tlist_member((Var *) clause, (List *) targetlist_so_far) == NULL)
-                       add_var_to_tlist(&tmp_rel, (Var *) clause);
-
-               return tmp_rel.targetlist;
-       }
-       else if (IsA(clause, Expr) && ! is_subplan(clause))
-       {
-               /*
-                * Recursively scan the arguments of an expression.
-                */
-               foreach(t, ((Expr *) clause)->args)
-                       targetlist_so_far = check_having_qual_for_vars(lfirst(t), targetlist_so_far);
-               return targetlist_so_far;
-       }
-       else if (IsA(clause, Aggref))
-       {
-               targetlist_so_far = check_having_qual_for_vars(((Aggref *) clause)->target, targetlist_so_far);
-               return targetlist_so_far;
-       }
-       else if (IsA(clause, ArrayRef))
-       {
-               ArrayRef   *aref = (ArrayRef *) clause;
-
-               /*
-                * This is an arrayref. Recursively call this routine for its
-                * expression and its index expression...
-                */
-               foreach(t, aref->refupperindexpr)
-                       targetlist_so_far = check_having_qual_for_vars(lfirst(t), targetlist_so_far);
-               foreach(t, aref->reflowerindexpr)
-                       targetlist_so_far = check_having_qual_for_vars(lfirst(t), targetlist_so_far);
-               targetlist_so_far = check_having_qual_for_vars(aref->refexpr, targetlist_so_far);
-               targetlist_so_far = check_having_qual_for_vars(aref->refassgnexpr, targetlist_so_far);
-
-               return targetlist_so_far;
-       }
-       else if (IsA(clause, Param) || IsA(clause, Const))
-       {
-               /* do nothing! */
-               return targetlist_so_far;
-       }
-       /*
-        * If we get to a sublink, then we only have to check the lefthand
-        * side of the expression to see if there are any additional VARs.
-        * QUESTION: can this code actually be hit?
-        */
-       else if (IsA(clause, SubLink))
-       {
-               foreach(t, ((SubLink *) clause)->lefthand)
-                       targetlist_so_far = check_having_qual_for_vars(lfirst(t), targetlist_so_far);
-               return targetlist_so_far;
-       }
-       else
-       {
-               /*
-                * Ooops! we can not handle that!
-                */
-               elog(ERROR, "check_having_qual_for_vars: Cannot handle node type %d",
-                        nodeTag(clause));
-               return NIL;
-       }
-}
-
 /*
  * check_having_for_ungrouped_vars takes the havingQual and the list of
  * GROUP BY clauses and checks for subplans in the havingQual that are being
@@ -1053,6 +971,15 @@ check_having_for_ungrouped_vars(Node *clause, List *groupClause)
                 * parser already checked 'em.
                 */
        }
+       else if (single_node(clause))
+       {
+               /* ignore */
+       }
+       else if (IsA(clause, Iter))
+       {
+               check_having_for_ungrouped_vars(((Iter *) clause)->iterexpr,
+                                                                               groupClause);
+       }
        else if (is_subplan(clause))
        {
                /*
@@ -1098,8 +1025,8 @@ check_having_for_ungrouped_vars(Node *clause, List *groupClause)
        }
        else if (IsA(clause, Aggref))
        {
-                       check_having_for_ungrouped_vars(((Aggref *) clause)->target,
-                                                                                       groupClause);
+               check_having_for_ungrouped_vars(((Aggref *) clause)->target,
+                                                                               groupClause);
        }
        else if (IsA(clause, ArrayRef))
        {
@@ -1116,15 +1043,19 @@ check_having_for_ungrouped_vars(Node *clause, List *groupClause)
                check_having_for_ungrouped_vars(aref->refexpr, groupClause);
                check_having_for_ungrouped_vars(aref->refassgnexpr, groupClause);
        }
-       else if (IsA(clause, Param) || IsA(clause, Const))
+       else if (case_clause(clause))
        {
-               /* do nothing! */
+               foreach(t, ((CaseExpr *) clause)->args)
+               {
+                       CaseWhen   *when = (CaseWhen *) lfirst(t);
+                       check_having_for_ungrouped_vars(when->expr, groupClause);
+                       check_having_for_ungrouped_vars(when->result, groupClause);
+               }
+               check_having_for_ungrouped_vars(((CaseExpr *) clause)->defresult,
+                                                                               groupClause);
        }
        else
        {
-               /*
-                * Ooops! we can not handle that!
-                */
                elog(ERROR, "check_having_for_ungrouped_vars: Cannot handle node type %d",
                         nodeTag(clause));
        }
index 914f33f50ea4f5f10aaf3a0a47e762fd61ab2569..b906f8e4c4823bf7959eccc5355d7e0f0ae8cd3c 100644 (file)
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.17 1999/02/22 05:26:27 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.18 1999/05/03 00:38:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -68,54 +68,56 @@ pull_varnos(Node *me)
 
 /*
  * contain_var_clause
- *       Recursively find var nodes from a clause by pulling vars from the
- *       left and right operands of the clause.
+ *       Recursively scan a clause to discover whether it contains any Var nodes.
  *
  *       Returns true if any varnode found.
  */
 bool
 contain_var_clause(Node *clause)
 {
+       List       *temp;
+
        if (clause == NULL)
                return FALSE;
        else if (IsA(clause, Var))
                return TRUE;
-       else if (IsA(clause, Iter))
-               return contain_var_clause(((Iter *) clause)->iterexpr);
        else if (single_node(clause))
                return FALSE;
-       else if (or_clause(clause) || and_clause(clause) || is_funcclause(clause))
+       else if (IsA(clause, Iter))
+               return contain_var_clause(((Iter *) clause)->iterexpr);
+       else if (is_subplan(clause))
        {
-               List       *temp;
-
                foreach(temp, ((Expr *) clause)->args)
                {
                        if (contain_var_clause(lfirst(temp)))
                                return TRUE;
                }
+               /* Also check left sides of Oper-s */
+               foreach(temp, ((SubPlan *) ((Expr *) clause)->oper)->sublink->oper)
+               {
+                       if (contain_var_clause(lfirst(((Expr *) lfirst(temp))->args)))
+                               return TRUE;
+               }
                return FALSE;
        }
-       else if (is_subplan(clause))
+       else if (IsA(clause, Expr))
        {
-               List       *temp;
-
+               /*
+                * Recursively scan the arguments of an expression.
+                * NOTE: this must come after is_subplan() case since
+                * subplan is a kind of Expr node.
+                */
                foreach(temp, ((Expr *) clause)->args)
                {
                        if (contain_var_clause(lfirst(temp)))
                                return TRUE;
                }
-               /* Ok - check left sides of Oper-s */
-               foreach(temp, ((SubPlan *) ((Expr *) clause)->oper)->sublink->oper)
-               {
-                       if (contain_var_clause(lfirst(((Expr *) lfirst(temp))->args)))
-                               return TRUE;
-               }
                return FALSE;
        }
+       else if (IsA(clause, Aggref))
+               return contain_var_clause(((Aggref *) clause)->target);
        else if (IsA(clause, ArrayRef))
        {
-               List       *temp;
-
                foreach(temp, ((ArrayRef *) clause)->refupperindexpr)
                {
                        if (contain_var_clause(lfirst(temp)))
@@ -132,19 +134,11 @@ contain_var_clause(Node *clause)
                        return TRUE;
                return FALSE;
        }
-       else if (not_clause(clause))
-               return contain_var_clause((Node *) get_notclausearg((Expr *) clause));
-       else if (is_opclause(clause))
-               return (contain_var_clause((Node *) get_leftop((Expr *) clause)) ||
-                         contain_var_clause((Node *) get_rightop((Expr *) clause)));
        else if (case_clause(clause))
        {
-               List       *args;
-               CaseWhen   *when;
-
-               foreach(args, ((CaseExpr *) clause)->args)
+               foreach(temp, ((CaseExpr *) clause)->args)
                {
-                       when = lfirst(args);
+                       CaseWhen   *when = (CaseWhen *) lfirst(temp);
                        if (contain_var_clause(when->expr))
                                return TRUE;
                        if (contain_var_clause(when->result))
@@ -152,6 +146,11 @@ contain_var_clause(Node *clause)
                }
                return (contain_var_clause(((CaseExpr *) clause)->defresult));
        }
+       else
+       {
+               elog(ERROR, "contain_var_clause: Cannot handle node type %d",
+                        nodeTag(clause));
+       }
 
        return FALSE;
 }
@@ -161,45 +160,46 @@ contain_var_clause(Node *clause)
  *       Recursively pulls all var nodes from a clause by pulling vars from the
  *       left and right operands of the clause.
  *
- *       Returns list of varnodes found.
+ *       Returns list of varnodes found.  Note the varnodes themselves are not
+ *       copied, only referenced.
  */
 List *
 pull_var_clause(Node *clause)
 {
        List       *retval = NIL;
+       List       *temp;
 
        if (clause == NULL)
                return NIL;
        else if (IsA(clause, Var))
                retval = lcons(clause, NIL);
-       else if (IsA(clause, Iter))
-               retval = pull_var_clause(((Iter *) clause)->iterexpr);
        else if (single_node(clause))
                retval = NIL;
-       else if (or_clause(clause) || and_clause(clause) || is_funcclause(clause))
-       {
-               List       *temp;
-
-               foreach(temp, ((Expr *) clause)->args)
-                       retval = nconc(retval, pull_var_clause(lfirst(temp)));
-       }
+       else if (IsA(clause, Iter))
+               retval = pull_var_clause(((Iter *) clause)->iterexpr);
        else if (is_subplan(clause))
        {
-               List       *temp;
-
                foreach(temp, ((Expr *) clause)->args)
                        retval = nconc(retval, pull_var_clause(lfirst(temp)));
-               /* Ok - get Var-s from left sides of Oper-s */
+               /* Also get Var-s from left sides of Oper-s */
                foreach(temp, ((SubPlan *) ((Expr *) clause)->oper)->sublink->oper)
                        retval = nconc(retval,
                                 pull_var_clause(lfirst(((Expr *) lfirst(temp))->args)));
        }
+       else if (IsA(clause, Expr))
+       {
+               /*
+                * Recursively scan the arguments of an expression.
+                * NOTE: this must come after is_subplan() case since
+                * subplan is a kind of Expr node.
+                */
+               foreach(temp, ((Expr *) clause)->args)
+                       retval = nconc(retval, pull_var_clause(lfirst(temp)));
+       }
        else if (IsA(clause, Aggref))
                retval = pull_var_clause(((Aggref *) clause)->target);
        else if (IsA(clause, ArrayRef))
        {
-               List       *temp;
-
                foreach(temp, ((ArrayRef *) clause)->refupperindexpr)
                        retval = nconc(retval, pull_var_clause(lfirst(temp)));
                foreach(temp, ((ArrayRef *) clause)->reflowerindexpr)
@@ -209,25 +209,21 @@ pull_var_clause(Node *clause)
                retval = nconc(retval,
                                   pull_var_clause(((ArrayRef *) clause)->refassgnexpr));
        }
-       else if (not_clause(clause))
-               retval = pull_var_clause((Node *) get_notclausearg((Expr *) clause));
-       else if (is_opclause(clause))
-               retval = nconc(pull_var_clause((Node *) get_leftop((Expr *) clause)),
-                                pull_var_clause((Node *) get_rightop((Expr *) clause)));
        else if (case_clause(clause))
        {
-               List       *temp;
-
                foreach(temp, ((CaseExpr *) clause)->args)
                {
-                       retval = nconc(retval, pull_var_clause(((CaseWhen *) lfirst(temp))->expr));
-                       retval = nconc(retval, pull_var_clause(((CaseWhen *) lfirst(temp))->result));
+                       CaseWhen   *when = (CaseWhen *) lfirst(temp);
+                       retval = nconc(retval, pull_var_clause(when->expr));
+                       retval = nconc(retval, pull_var_clause(when->result));
                }
-
                retval = nconc(retval, pull_var_clause(((CaseExpr *) clause)->defresult));
        }
        else
-               retval = NIL;
+       {
+               elog(ERROR, "pull_var_clause: Cannot handle node type %d",
+                        nodeTag(clause));
+       }
 
        return retval;
 }
index 44dad8cfd66daaa28167cc9026edc01a1542ab76..002238571c0a3baaeff9d96257960f5cb6d7ce33 100644 (file)
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: planmain.h,v 1.23 1999/04/19 01:43:10 tgl Exp $
+ * $Id: planmain.h,v 1.24 1999/05/03 00:38:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -54,9 +54,14 @@ extern List *join_references(List *clauses, List *outer_tlist,
                                                         List *inner_tlist);
 extern List *index_outerjoin_references(List *inner_indxqual,
                                                   List *outer_tlist, Index inner_relid);
+extern void replace_tlist_with_subplan_refs(List *tlist,
+                                                                                       Index subvarno,
+                                                                                       List *subplanTargetList);
+extern void replace_vars_with_subplan_refs(Node *clause,
+                                                                                  Index subvarno,
+                                                                                  List *subplanTargetList);
 extern bool set_agg_tlist_references(Agg *aggNode);
 extern void del_agg_tlist_references(List *tlist);
-extern List *check_having_qual_for_vars(Node *clause, List *targetlist_so_far);
 extern void check_having_for_ungrouped_vars(Node *clause, List *groupClause);
 extern void transformKeySetQuery(Query *origNode);