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Fix GroupBy: enable functions over aggregates and GroupBy-ed fields

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This commit is contained in:
Vadim B. Mikheev 1997-04-29 04:32:50 +00:00
parent f4279c46e7
commit a1fbd470a9
3 changed files with 87 additions and 66 deletions
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71
src/backend/optimizer/plan/planmain.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.3 1997/04/05 06:37:37 vadim Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.4 1997/04/29 04:32:50 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@ -359,8 +359,9 @@ make_groupPlan(List **tlist,
List *sort_tlist;
List *sl, *gl;
List *glc = listCopy (groupClause);
List *aggvals = NIL; /* list of vars of aggregates */
int aggvcnt;
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;
@ -375,7 +376,8 @@ make_groupPlan(List **tlist,
/*
* Make template TL for subplan, Sort & Group:
* 1. Take away Aggregates and re-set resno-s accordantly.
* 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
@ -390,7 +392,7 @@ make_groupPlan(List **tlist,
{
GroupClause *grpcl = (GroupClause*)lfirst(gl);
if ( grpcl->resdom->resno == te->resdom->resno )
if ( grpcl->entry->resdom->resno == te->resdom->resno )
{
resdom = te->resdom;
@ -403,15 +405,20 @@ make_groupPlan(List **tlist,
break;
}
}
if ( resdom == NULL ) /* Not GroupBy-ed entry: remove */
{ /* aggregate(s) from Group/Sort TL */
if ( IsA (te->expr, Aggreg) )
{ /* save Aggregate' Vars */
aggvals = nconc (aggvals, pull_var_clause (te->expr));
sort_tlist = lremove (lfirst (sl), sort_tlist);
/*
* 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
resdom->resno = last_resno++; /* re-set */
te->resdom->resno = last_resno++;
}
}
@ -421,12 +428,12 @@ make_groupPlan(List **tlist,
}
/*
* Aggregates 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.
* 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.
*/
aggvcnt = length (aggvals);
foreach (gl, aggvals)
otlvcnt = length (otlvars);
foreach (gl, otlvars)
{
Var *v = (Var*)lfirst (gl);
@ -437,9 +444,9 @@ make_groupPlan(List **tlist,
last_resno++;
}
else /* already in TL */
aggvcnt--;
otlvcnt--;
}
/* Now aggvcnt is number of Vars added in TL for Aggregates */
/* 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);
@ -489,17 +496,28 @@ make_groupPlan(List **tlist,
grpColIdx, sortplan);
/*
* Make TL for parent: "restore" Aggregates and
* resno-s of others accordantly.
* 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);
if ( !IsA (te->expr, Aggreg) ) /* It's "our" TLE - we're to return */
{ /* it from Sort/Group plans */
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" */
@ -508,15 +526,16 @@ make_groupPlan(List **tlist,
sort_tlist = lappend (sort_tlist, my);
continue;
}
/* TLE of an aggregate */
/* else - it's TLE of an non-GroupBy entry */
sort_tlist = lappend (sort_tlist, copyObject(te));
}
/*
* Pure aggregates Vars were at the end of Group' TL.
* 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 ( aggvcnt == length (sl) );
Assert ( otlvcnt == length (sl) );
Assert ( length (otles) == 0 );
*tlist = sort_tlist;

78
src/backend/parser/analyze.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.26 1997/04/27 19:16:44 thomas Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.27 1997/04/29 04:32:26 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@ -1552,7 +1552,8 @@ transformGroupClause(ParseState *pstate, List *grouplist, List *targetlist)
if (restarget == NULL)
elog(WARN,"The field being grouped by must appear in the target list");
grpcl->resdom = resdom = restarget->resdom;
grpcl->entry = restarget;
resdom = restarget->resdom;
grpcl->grpOpoid = oprid(oper("<",
resdom->restype,
resdom->restype,false));
@ -2359,6 +2360,39 @@ contain_agg_clause(Node *clause)
return FALSE;
}
/*
* exprIsAggOrGroupCol -
* returns true if the expression does not contain non-group columns.
*/
static bool
exprIsAggOrGroupCol(Node *expr, List *groupClause)
{
List *gl;
if ( expr == NULL || IsA (expr, Const) || IsA (expr, Aggreg) )
return TRUE;
foreach (gl, groupClause)
{
GroupClause *grpcl = lfirst(gl);
if ( equal (expr, grpcl->entry->expr) )
return TRUE;
}
if ( IsA (expr, Expr) )
{
List *temp;
foreach (temp, ((Expr*)expr)->args)
if (!exprIsAggOrGroupCol(lfirst(temp),groupClause))
return FALSE;
return TRUE;
}
return FALSE;
}
/*
* tleIsAggOrGroupCol -
* returns true if the TargetEntry is Agg or GroupCol.
@ -2376,9 +2410,9 @@ tleIsAggOrGroupCol(TargetEntry *tle, List *groupClause)
{
GroupClause *grpcl = lfirst(gl);
if ( tle->resdom->resno == grpcl->resdom->resno )
if ( tle->resdom->resno == grpcl->entry->resdom->resno )
{
if ( IsA (expr, Aggreg) )
if ( contain_agg_clause ((Node*) expr) )
elog (WARN, "parser: aggregates not allowed in GROUP BY clause");
return TRUE;
}
@ -2387,39 +2421,8 @@ tleIsAggOrGroupCol(TargetEntry *tle, List *groupClause)
if ( IsA (expr, Aggreg) )
return TRUE;
return FALSE;
}
#if 0 /* Now GroupBy contains resdom to enable Group By func_results */
/*
* exprIsAggOrGroupCol -
* returns true if the expression does not contain non-group columns.
*/
static bool
exprIsAggOrGroupCol(Node *expr, List *groupClause)
{
if (expr==NULL)
return TRUE;
else if (IsA(expr,Const))
return TRUE;
else if (IsA(expr,Var)) {
List *gl;
Var *var = (Var*)expr;
/*
* only group columns are legal
*/
foreach (gl, groupClause) {
GroupClause *grpcl = lfirst(gl);
if ((grpcl->grpAttr->varno == var->varno) &&
(grpcl->grpAttr->varattno == var->varattno))
return TRUE;
}
return FALSE;
} else if (IsA(expr,Aggreg))
/* aggregates can take group column or non-group column as argument,
no further check necessary. */
return TRUE;
else if (IsA(expr,Expr)) {
if ( IsA (expr, Expr) )
{
List *temp;
foreach (temp, ((Expr*)expr)->args)
@ -2430,7 +2433,6 @@ exprIsAggOrGroupCol(Node *expr, List *groupClause)
return FALSE;
}
#endif
/*
* parseCheckAggregates -

4
src/include/nodes/parsenodes.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: parsenodes.h,v 1.14 1997/04/23 05:58:06 vadim Exp $
* $Id: parsenodes.h,v 1.15 1997/04/29 04:28:59 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@ -774,7 +774,7 @@ typedef struct SortClause {
*/
typedef struct GroupClause {
NodeTag type;
Resdom *resdom; /* attributes to group on */
TargetEntry *entry; /* attributes to group on */
Oid grpOpoid; /* the sort operator to use */
} GroupClause;