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Implement feature of new FE/BE protocol whereby RowDescription identifies

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the column by table OID and column number, if it's a simple column
reference.  Along the way, get rid of reskey/reskeyop fields in Resdoms.
Turns out that representation was not convenient for either the planner
or the executor; we can make the planner deliver exactly what the
executor wants with no more effort.
initdb forced due to change in stored rule representation.
This commit is contained in:
Tom Lane
2003-05-06 00:20:33 +00:00
parent 94a3c60324
commit 2cf57c8f8d
32 changed files with 454 additions and 336 deletions
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91
src/backend/parser/parse_target.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.100 2003/04/29 22:13:10 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.101 2003/05/06 00:20:32 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -26,6 +26,7 @@
#include "utils/builtins.h"
static void markTargetListOrigin(ParseState *pstate, Resdom *res, Var *var);
static List *ExpandAllTables(ParseState *pstate);
static char *FigureColname(Node *node);
static int FigureColnameInternal(Node *node, char **name);
@ -204,6 +205,94 @@ transformTargetList(ParseState *pstate, List *targetlist)
}
/*
* markTargetListOrigins()
* Mark targetlist columns that are simple Vars with the source
* table's OID and column number.
*
* Currently, this is done only for SELECT targetlists, since we only
* need the info if we are going to send it to the frontend.
*/
void
markTargetListOrigins(ParseState *pstate, List *targetlist)
{
List *l;
foreach(l, targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
markTargetListOrigin(pstate, tle->resdom, (Var *) tle->expr);
}
}
/*
* markTargetListOrigin()
* If 'var' is a Var of a plain relation, mark 'res' with its origin
*
* This is split out so it can recurse for join references. Note that we
* do not drill down into views, but report the view as the column owner.
*/
static void
markTargetListOrigin(ParseState *pstate, Resdom *res, Var *var)
{
RangeTblEntry *rte;
AttrNumber attnum;
if (var == NULL || !IsA(var, Var))
return;
Assert(var->varno > 0 &&
(int) var->varno <= length(pstate->p_rtable));
rte = rt_fetch(var->varno, pstate->p_rtable);
attnum = var->varattno;
switch (rte->rtekind)
{
case RTE_RELATION:
/* It's a table or view, report it */
res->resorigtbl = rte->relid;
res->resorigcol = attnum;
break;
case RTE_SUBQUERY:
{
/* Subselect-in-FROM: copy up from the subselect */
List *subtl;
foreach(subtl, rte->subquery->targetList)
{
TargetEntry *subte = (TargetEntry *) lfirst(subtl);
if (subte->resdom->resjunk ||
subte->resdom->resno != attnum)
continue;
res->resorigtbl = subte->resdom->resorigtbl;
res->resorigcol = subte->resdom->resorigcol;
break;
}
/* falling off end of list shouldn't happen... */
if (subtl == NIL)
elog(ERROR, "Subquery %s does not have attribute %d",
rte->eref->aliasname, attnum);
}
break;
case RTE_JOIN:
{
/* Join RTE --- recursively inspect the alias variable */
Var *aliasvar;
Assert(attnum > 0 && attnum <= length(rte->joinaliasvars));
aliasvar = (Var *) nth(attnum - 1, rte->joinaliasvars);
markTargetListOrigin(pstate, res, aliasvar);
}
break;
case RTE_SPECIAL:
case RTE_FUNCTION:
/* not a simple relation, leave it unmarked */
break;
}
}
/*
* updateTargetListEntry()
* This is used in INSERT and UPDATE statements only. It prepares a