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Hi! 

INTERSECT and EXCEPT is available for postgresql-v6.4!

The patch against v6.4 is included at the end of the current text
(in uuencoded form!)

I also included the text of my Master's Thesis. (a postscript
version). I hope that you find something of it useful and would be
happy if parts of it find their way into the PostgreSQL documentation
project (If so, tell me, then I send the sources of the document!)

The contents of the document are:
  -) The first chapter might be of less interest as it gives only an
     overview on SQL.

  -) The second chapter gives a description on much of PostgreSQL's
     features (like user defined types etc. and how to use these features)

  -) The third chapter starts with an overview of PostgreSQL's internal
     structure with focus on the stages a query has to pass (i.e. parser,
     planner/optimizer, executor). Then a detailed description of the
     implementation of the Having clause and the Intersect/Except logic is
     given.

Originally I worked on v6.3.2 but never found time enough to prepare
and post a patch. Now I applied the changes to v6.4 to get Intersect
and Except working with the new version. Chapter 3 of my documentation
deals with the changes against v6.3.2, so keep that in mind when
comparing the parts of the code printed there with the patched sources
of v6.4.

Here are some remarks on the patch. There are some things that have
still to be done but at the moment I don't have time to do them
myself. (I'm doing my military service at the moment) Sorry for that
:-(

-) I used a rewrite technique for the implementation of the Except/Intersect
   logic which rewrites the query to a semantically equivalent query before
   it is handed to the rewrite system (for views, rules etc.), planner,
   executor etc.

-) In v6.3.2 the types of the attributes of two select statements
   connected by the UNION keyword had to match 100%. In v6.4 the types
   only need to be familiar (i.e. int and float can be mixed). Since this
   feature did not exist when I worked on Intersect/Except it
   does not work correctly for Except/Intersect queries WHEN USED IN
   COMBINATION WITH UNIONS! (i.e. sometimes the wrong type is used for the
   resulting table. This is because until now the types of the attributes of
   the first select statement have been used for the resulting table.
   When Intersects and/or Excepts are used in combination with Unions it
   might happen, that the first select statement of the original query
   appears at another position in the query which will be executed. The reason
   for this is the technique used for the implementation of
   Except/Intersect which does a query rewrite!)
   NOTE: It is NOT broken for pure UNION queries and pure INTERSECT/EXCEPT
         queries!!!

-) I had to add the field intersect_clause to some data structures
   but did not find time to implement printfuncs for the new field.
   This does NOT break the debug modes but when an Except/Intersect
   is used the query debug output will be the already rewritten query.

-) Massive changes to the grammar rules for SELECT and INSERT statements
   have been necessary (see comments in gram.y and documentation for
   deatails) in order to be able to use mixed queries like
   (SELECT ... UNION (SELECT ... EXCEPT SELECT)) INTERSECT SELECT...;

-) When using UNION/EXCEPT/INTERSECT you will get:
   NOTICE: equal: "Don't know if nodes of type xxx are equal".
   I did not have  time to add comparsion support for all the needed nodes,
   but the default behaviour of the function equal met my requirements.
   I did not dare to supress this message!

   That's the reason why the regression test for union will fail: These
   messages are also included in the union.out file!

-) Somebody of you changed the union_planner() function for v6.4
   (I copied the targetlist to new_tlist and that was removed and
   replaced by a cleanup of the original targetlist). These chnages
   violated some having queries executed against views so I changed
   it back again. I did not have time to examine the differences between the
   two versions but now it works :-)
   If you want to find out, try the file queries/view_having.sql on
   both versions and compare the results . Two queries won't produce a
   correct result with your version.

regards

    Stefan
This commit is contained in:
Bruce Momjian 1999-01-18 00:10:17 +00:00
parent 52065cf347
commit bd8ffc6f3f
19 changed files with 1275 additions and 485 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
src/backend/executor/execAmi.c
View File

@ -5,7 +5,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: execAmi.c,v 1.28 1998/12/14 08:11:02 scrappy Exp $
* $Id: execAmi.c,v 1.29 1999/01/18 00:09:45 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -39,6 +39,9 @@
#include "executor/nodeNestloop.h"
#include "executor/nodeHashjoin.h"
#include "executor/nodeHash.h"
/***S*I***/
#include "executor/nodeGroup.h"
#include "executor/nodeAgg.h"
#include "executor/nodeGroup.h"
#include "executor/nodeResult.h"

5
src/backend/executor/nodeAgg.c
View File

@ -491,7 +491,10 @@ ExecAgg(Agg *node)
* As long as the retrieved group does not match the
* qualifications it is ignored and the next group is fetched
*/
qual_result = ExecQual(fix_opids(node->plan.qual), econtext);
if(node->plan.qual != NULL){
qual_result = ExecQual(fix_opids(node->plan.qual), econtext);
}
if (oneTuple)
pfree(oneTuple);
}

5
src/backend/nodes/outfuncs.c
View File

@ -5,7 +5,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: outfuncs.c,v 1.58 1998/12/20 07:13:36 scrappy Exp $
* $Id: outfuncs.c,v 1.59 1999/01/18 00:09:45 momjian Exp $
*
* NOTES
* Every (plan) node in POSTGRES has an associated "out" routine which
@ -227,6 +227,9 @@ _outQuery(StringInfo str, Query *node)
node->hasSubLinks ? "true" : "false");
_outNode(str, node->unionClause);
appendStringInfo(str, " :intersectClause ");
_outNode(str, node->intersectClause);
appendStringInfo(str, " :limitOffset ");
_outNode(str, node->limitOffset);

7
src/backend/nodes/readfuncs.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.40 1998/12/14 00:01:47 thomas Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.41 1999/01/18 00:09:46 momjian Exp $
*
* NOTES
* Most of the read functions for plan nodes are tested. (In fact, they
@ -163,6 +163,11 @@ _readQuery()
token = lsptok(NULL, &length); /* skip :unionClause */
local_node->unionClause = nodeRead(true);
/***S*I***/
token = lsptok(NULL, &length); /* skip :intersectClause */
local_node->intersectClause = nodeRead(true);
token = lsptok(NULL, &length); /* skip :limitOffset */
local_node->limitOffset = nodeRead(true);

261
src/backend/optimizer/plan/planner.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.35 1998/09/09 03:48:01 vadim Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.36 1999/01/18 00:09:47 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -95,20 +95,26 @@ Plan *
union_planner(Query *parse)
{
List *tlist = parse->targetList;
int tlist_len = length(tlist);
List *rangetable = parse->rtable;
Plan *result_plan = (Plan *) NULL;
Index rt_index;
/***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;
Index rt_index;
if (parse->unionClause)
{
result_plan = (Plan *) plan_union_queries(parse);
/* XXX do we need to do this? bjm 12/19/97 */
tlist = preprocess_targetlist(tlist,
parse->commandType,
parse->resultRelation,
parse->rtable);
result_plan = (Plan *) plan_union_queries(parse);
/* 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_inherit_rt_entry(rangetable)) != -1)
@ -116,47 +122,65 @@ union_planner(Query *parse)
result_plan = (Plan *) plan_inherit_queries(parse, rt_index);
/* XXX do we need to do this? bjm 12/19/97 */
tlist = preprocess_targetlist(tlist,
parse->commandType,
parse->resultRelation,
parse->rtable);
parse->commandType,
parse->resultRelation,
parse->rtable);
}
else
{
List **vpm = NULL;
/*
* check_having_qual_for_vars takes the havingQual and the tlist
* as arguments and recursively scans the havingQual for VAR nodes
* that are not contained in tlist yet. If so, it creates a new entry
* and attaches it to the tlist. Latter, we use tlist_len to
* truncate tlist - ie restore actual tlist...
*/
if (parse->hasAggs)
List **vpm = NULL;
/***S*H***/
/* This is only necessary if aggregates are in use in queries like:
* SELECT sid
* FROM part
* GROUP BY sid
* HAVING MIN(pid) > 1; (pid is used but never selected for!!!)
* because the function 'query_planner' creates the plan for the lefttree
* of the 'GROUP' node and returns only those attributes contained in 'tlist'.
* The original 'tlist' contains only 'sid' here and that's why we have to
* to extend it to attributes which are not selected but are used in the
* havingQual. */
/* 'check_having_qual_for_vars' takes the havingQual and the actual 'tlist'
* as arguments and recursively scans the havingQual for attributes
* (VAR nodes) that are not contained in 'tlist' yet. If so, it creates
* a new entry and attaches it to the list 'new_tlist' (consisting of the
* VAR node and the RESDOM node as usual with tlists :-) ) */
if (parse->hasAggs)
{
if (parse->havingQual != NULL)
{
if (parse->havingQual != NULL)
tlist = check_having_qual_for_vars(parse->havingQual, tlist);
new_tlist = check_having_qual_for_vars(parse->havingQual,new_tlist);
}
tlist = preprocess_targetlist(tlist,
parse->commandType,
parse->resultRelation,
parse->rtable);
if (parse->rtable != NULL)
{
vpm = (List **) palloc(length(parse->rtable) * sizeof(List *));
memset(vpm, 0, length(parse->rtable) * sizeof(List *));
}
PlannerVarParam = lcons(vpm, PlannerVarParam);
result_plan = query_planner(parse,
parse->commandType,
tlist,
(List *) parse->qual);
PlannerVarParam = lnext(PlannerVarParam);
if (vpm != NULL)
pfree(vpm);
}
new_tlist = preprocess_targetlist(new_tlist,
parse->commandType,
parse->resultRelation,
parse->rtable);
/* Here starts the original (pre having) code */
tlist = preprocess_targetlist(tlist,
parse->commandType,
parse->resultRelation,
parse->rtable);
if (parse->rtable != NULL)
{
vpm = (List **) palloc(length(parse->rtable) * sizeof(List *));
memset(vpm, 0, length(parse->rtable) * sizeof(List *));
}
PlannerVarParam = lcons(vpm, PlannerVarParam);
result_plan = query_planner(parse,
parse->commandType,
new_tlist,
(List *) parse->qual);
PlannerVarParam = lnext(PlannerVarParam);
if (vpm != NULL)
pfree(vpm);
}
/*
* If we have a GROUP BY clause, insert a group node (with the
* appropriate sort node.)
@ -173,8 +197,10 @@ union_planner(Query *parse)
*/
tuplePerGroup = parse->hasAggs;
/***S*H***/
/* Use 'new_tlist' instead of 'tlist' */
result_plan =
make_groupPlan(&tlist,
make_groupPlan(&new_tlist,
tuplePerGroup,
parse->groupClause,
result_plan);
@ -185,6 +211,11 @@ union_planner(Query *parse)
*/
if (parse->hasAggs)
{
int old_length=0, new_length=0;
/* Create the AGG node but use 'tlist' not 'new_tlist' as target list because we
* don't want the additional attributes (only used for the havingQual, see above)
* to show up in the result */
result_plan = (Plan *) make_agg(tlist, result_plan);
/*
@ -192,78 +223,74 @@ union_planner(Query *parse)
* the result tuple of the subplans.
*/
((Agg *) result_plan)->aggs =
set_agg_tlist_references((Agg *) result_plan);
set_agg_tlist_references((Agg *) result_plan);
if (parse->havingQual != NULL)
{
List *clause;
List **vpm = NULL;
/***S*H***/
if(parse->havingQual!=NULL)
{
List *clause;
List **vpm = NULL;
/* stuff copied from above to handle the use of attributes from outside
* in subselects */
/*
* Restore target list: get rid of Vars added for havingQual.
* Assumption: tlist_len > 0...
*/
{
List *l;
int tlen = 0;
if (parse->rtable != NULL)
{
vpm = (List **) palloc(length(parse->rtable) * sizeof(List *));
memset(vpm, 0, length(parse->rtable) * sizeof(List *));
}
PlannerVarParam = lcons(vpm, PlannerVarParam);
/* convert the havingQual to conjunctive normal form (cnf) */
(List *) parse->havingQual=cnfify((Expr *)(Node *) parse->havingQual,true);
/* There is a subselect in the havingQual, so we have to process it
* using the same function as for a subselect in 'where' */
if (parse->hasSubLinks)
{
(List *) parse->havingQual =
(List *) SS_process_sublinks((Node *) parse->havingQual);
}
/* Calculate the opfids from the opnos (=select the correct functions for
* the used VAR datatypes) */
(List *) parse->havingQual=fix_opids((List *) parse->havingQual);
((Agg *) result_plan)->plan.qual=(List *) parse->havingQual;
/* Check every clause of the havingQual for aggregates used and append
* them to result_plan->aggs */
foreach(clause, ((Agg *) result_plan)->plan.qual)
{
/* Make sure there are aggregates in the havingQual
* if so, the list must be longer after check_having_qual_for_aggs */
old_length=length(((Agg *) result_plan)->aggs);
foreach (l, ((Agg *) result_plan)->plan.targetlist)
{
if (++tlen == tlist_len)
break;
}
lnext(l) = NIL;
}
/*
* stuff copied from above to handle the use of attributes
* from outside in subselects
*/
if (parse->rtable != NULL)
{
vpm = (List **) palloc(length(parse->rtable) * sizeof(List *));
memset(vpm, 0, length(parse->rtable) * sizeof(List *));
}
PlannerVarParam = lcons(vpm, PlannerVarParam);
/*
* There is a subselect in the havingQual, so we have to
* process it using the same function as for a subselect in
* 'where'
*/
if (parse->hasSubLinks)
parse->havingQual = SS_process_sublinks((Node *) parse->havingQual);
/* convert the havingQual to conjunctive normal form (cnf) */
parse->havingQual = (Node *) cnfify((Expr *) (Node *) parse->havingQual, true);
/*
* Calculate the opfids from the opnos (=select the correct
* functions for the used VAR datatypes)
*/
parse->havingQual = (Node *) fix_opids((List *) parse->havingQual);
((Agg *) result_plan)->plan.qual = (List *) parse->havingQual;
/*
* Check every clause of the havingQual for aggregates used
* and append them to result_plan->aggs
*/
foreach(clause, ((Agg *) result_plan)->plan.qual)
{
((Agg *) result_plan)->aggs = nconc(((Agg *) result_plan)->aggs,
check_having_qual_for_aggs((Node *) lfirst(clause),
((Agg *) result_plan)->plan.lefttree->targetlist,
((List *) parse->groupClause)));
}
PlannerVarParam = lnext(PlannerVarParam);
if (vpm != NULL)
pfree(vpm);
}
}
((Agg *) result_plan)->aggs = nconc(((Agg *) result_plan)->aggs,
check_having_qual_for_aggs((Node *) lfirst(clause),
((Agg *) result_plan)->plan.lefttree->targetlist,
((List *) parse->groupClause)));
/* Have a look at the length of the returned list. If there is no
* difference, no aggregates have been found and that means, that
* the Qual belongs to the where clause */
if (((new_length=length(((Agg *) result_plan)->aggs)) == old_length) ||
(new_length == 0))
{
elog(ERROR,"This could have been done in a where clause!!");
return (Plan *)NIL;
}
}
PlannerVarParam = lnext(PlannerVarParam);
if (vpm != NULL)
pfree(vpm);
}
}
/*
* For now, before we hand back the plan, check to see if there is a
* user-specified sort that needs to be done. Eventually, this will
@ -277,14 +304,14 @@ union_planner(Query *parse)
{
Plan *sortplan = make_sortplan(tlist, parse->sortClause, result_plan);
return (Plan *) make_unique(tlist, sortplan, parse->uniqueFlag);
return ((Plan *) make_unique(tlist, sortplan, parse->uniqueFlag));
}
else
{
if (parse->sortClause)
return make_sortplan(tlist, parse->sortClause, result_plan);
return (make_sortplan(tlist, parse->sortClause, result_plan));
else
return (Plan *) result_plan;
return ((Plan *) result_plan);
}
}

417
src/backend/optimizer/plan/setrefs.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.29 1998/12/14 00:02:10 thomas Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.30 1999/01/18 00:09:48 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -923,173 +923,195 @@ del_agg_clause(Node *clause)
return NULL;
}
/***S*H***/
/* check_having_qual_for_vars takes the the havingQual and the actual targetlist as arguments
* and recursively scans the havingQual for attributes that are not included in the targetlist
* yet. Attributes contained in the havingQual but not in the targetlist show up with queries
* like:
* SELECT sid
* like:
* SELECT sid
* FROM part
* GROUP BY sid
* HAVING MIN(pid) > 1; (pid is used but never selected for!!!).
* HAVING MIN(pid) > 1; (pid is used but never selected for!!!).
* 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. */
* (which will be the one used for the GROUP node later on) by these attributes. */
List *
check_having_qual_for_vars(Node *clause, List *targetlist_so_far)
{
List *t;
List *t;
if (IsA(clause, Var))
if (IsA(clause, Var))
{
RelOptInfo tmp_rel;
tmp_rel.targetlist = targetlist_so_far;
/*
* Ha! A Var node!
*/
/* Check if the VAR is already contained in the targetlist */
if (tlist_member((Var *)clause, (List *)targetlist_so_far) == NULL)
{
RelOptInfo tmp_rel;
tmp_rel.targetlist = targetlist_so_far;
/*
* Ha! A Var node!
*/
/* Check if the VAR is already contained in the targetlist */
if (tlist_member((Var *) clause, (List *) targetlist_so_far) == NULL)
add_tl_element(&tmp_rel, (Var *) clause);
return tmp_rel.targetlist;
}
else if (is_funcclause(clause) || not_clause(clause) ||
or_clause(clause) || and_clause(clause))
add_tl_element(&tmp_rel, (Var *)clause);
}
return tmp_rel.targetlist;
}
else if (is_funcclause(clause) || not_clause(clause) ||
or_clause(clause) || and_clause(clause))
{
/*
* This is a function. Recursively call this routine for its
* arguments...
*/
foreach(t, ((Expr *) clause)->args)
{
/*
* This is a function. Recursively call this routine for its
* arguments...
*/
foreach(t, ((Expr *) clause)->args)
targetlist_so_far = check_having_qual_for_vars(lfirst(t), targetlist_so_far);
return targetlist_so_far;
targetlist_so_far = check_having_qual_for_vars(lfirst(t), targetlist_so_far);
}
else if (IsA(clause, Aggreg))
return targetlist_so_far;
}
else if (IsA(clause, Aggreg))
{
targetlist_so_far =
check_having_qual_for_vars(((Aggreg *) 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(((Aggreg *) clause)->target, targetlist_so_far);
return targetlist_so_far;
targetlist_so_far = check_having_qual_for_vars(lfirst(t), targetlist_so_far);
}
else if (IsA(clause, ArrayRef))
foreach(t, aref->reflowerindexpr)
{
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;
targetlist_so_far = check_having_qual_for_vars(lfirst(t), targetlist_so_far);
}
else if (is_opclause(clause))
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 (is_opclause(clause))
{
/*
* This is an operator. Recursively call this routine for both its
* left and right operands
*/
Node *left = (Node *) get_leftop((Expr *) clause);
Node *right = (Node *) get_rightop((Expr *) clause);
if (left != (Node *) NULL)
targetlist_so_far = check_having_qual_for_vars(left, targetlist_so_far);
if (right != (Node *) NULL)
targetlist_so_far = check_having_qual_for_vars(right, 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 */
else if (IsA(clause, SubLink))
{
foreach(t,((List *)((SubLink *)clause)->lefthand))
{
/*
* This is an operator. Recursively call this routine for both its
* left and right operands
*/
Node *left = (Node *) get_leftop((Expr *) clause);
Node *right = (Node *) get_rightop((Expr *) clause);
if (left != (Node *) NULL)
targetlist_so_far = check_having_qual_for_vars(left, targetlist_so_far);
if (right != (Node *) NULL)
targetlist_so_far = check_having_qual_for_vars(right, 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
*/
else if (IsA(clause, SubLink))
{
foreach(t, ((List *) ((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: Can not handle this having_qual! %d\n",
nodeTag(clause));
return NIL;
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: Can not handle this having_qual! %d\n",
nodeTag(clause));
return NIL;
}
}
/* check_having_qual_for_aggs takes the havingQual, the targetlist and the groupClause
/* check_having_qual_for_aggs takes the havingQual, the targetlist and the groupClause
* as arguments and scans the havingQual recursively for aggregates. If an aggregate is
* found it is attached to a list and returned by the function. (All the returned lists
* found it is attached to a list and returned by the function. (All the returned lists
* are concenated to result_plan->aggs in planner.c:union_planner() */
List *
check_having_qual_for_aggs(Node *clause, List *subplanTargetList, List *groupClause)
{
List *t,
*l1;
List *t, *l1;
List *agg_list = NIL;
int contained_in_group_clause = 0;
int contained_in_group_clause = 0;
if (IsA(clause, Var))
{
TargetEntry *subplanVar;
TargetEntry *subplanVar;
/*
* Ha! A Var node!
*/
subplanVar = match_varid((Var *) clause, subplanTargetList);
/*
* Change the varno & varattno fields of the var node to point to the resdom->resno
* fields of the subplan (lefttree)
*/
((Var *) clause)->varattno = subplanVar->resdom->resno;
/*
* Ha! A Var node!
*/
subplanVar = match_varid((Var *) clause, subplanTargetList);
/*
* Change the varno & varattno fields of the var node to point to
* the resdom->resno fields of the subplan (lefttree)
*/
((Var *) clause)->varattno = subplanVar->resdom->resno;
return NIL;
return NIL;
}
else if (is_funcclause(clause) || not_clause(clause) ||
or_clause(clause) || and_clause(clause))
/***S*H***/
else if (is_funcclause(clause) || not_clause(clause) ||
or_clause(clause) || and_clause(clause))
{
int new_length=0, old_length=0;
/*
* This is a function. Recursively call this routine for its
* arguments... (i.e. for AND, OR, ... clauses!)
*/
foreach(t, ((Expr *) clause)->args)
{
agg_list = nconc(agg_list,
check_having_qual_for_aggs(lfirst(t), subplanTargetList,
groupClause));
old_length=length((List *)agg_list);
agg_list = nconc(agg_list,
check_having_qual_for_aggs(lfirst(t), subplanTargetList,
groupClause));
/* The arguments of OR or AND clauses are comparisons or relations
* and because we are in the havingQual there must be at least one operand
* using an aggregate function. If so, we will find it and the length of the
* agg_list will be increased after the above call to
* check_having_qual_for_aggs. If there are no aggregates used, the query
* could have been formulated using the 'where' clause */
if(((new_length=length((List *)agg_list)) == old_length) || (new_length == 0))
{
elog(ERROR,"This could have been done in a where clause!!");
return NIL;
}
}
return agg_list;
}
else if (IsA(clause, Aggreg))
{
return lcons(clause,
check_having_qual_for_aggs(((Aggreg *) clause)->target, subplanTargetList,
groupClause));
check_having_qual_for_aggs(((Aggreg *) clause)->target, subplanTargetList,
groupClause));
}
else if (IsA(clause, ArrayRef))
{
@ -1102,21 +1124,21 @@ check_having_qual_for_aggs(Node *clause, List *subplanTargetList, List *groupCla
foreach(t, aref->refupperindexpr)
{
agg_list = nconc(agg_list,
check_having_qual_for_aggs(lfirst(t), subplanTargetList,
groupClause));
check_having_qual_for_aggs(lfirst(t), subplanTargetList,
groupClause));
}
foreach(t, aref->reflowerindexpr)
{
agg_list = nconc(agg_list,
check_having_qual_for_aggs(lfirst(t), subplanTargetList,
groupClause));
check_having_qual_for_aggs(lfirst(t), subplanTargetList,
groupClause));
}
agg_list = nconc(agg_list,
check_having_qual_for_aggs(aref->refexpr, subplanTargetList,
groupClause));
check_having_qual_for_aggs(aref->refexpr, subplanTargetList,
groupClause));
agg_list = nconc(agg_list,
check_having_qual_for_aggs(aref->refassgnexpr, subplanTargetList,
groupClause));
check_having_qual_for_aggs(aref->refassgnexpr, subplanTargetList,
groupClause));
return agg_list;
}
@ -1132,85 +1154,92 @@ check_having_qual_for_aggs(Node *clause, List *subplanTargetList, List *groupCla
if (left != (Node *) NULL)
agg_list = nconc(agg_list,
check_having_qual_for_aggs(left, subplanTargetList,
groupClause));
check_having_qual_for_aggs(left, subplanTargetList,
groupClause));
if (right != (Node *) NULL)
agg_list = nconc(agg_list,
check_having_qual_for_aggs(right, subplanTargetList,
groupClause));
groupClause));
return agg_list;
}
else if (IsA(clause, Param) ||IsA(clause, Const))
else if (IsA(clause, Param) || IsA(clause, Const))
{
/* do nothing! */
return NIL;
}
/*
* This is for Sublinks which show up as EXPR nodes. All the other
* EXPR nodes (funcclauses, and_clauses, or_clauses) were caught above
*/
/* This is for Sublinks which show up as EXPR nodes. All the other EXPR nodes
* (funcclauses, and_clauses, or_clauses) were caught above */
else if (IsA(clause, Expr))
{
{
/* Only the lefthand side of the sublink has to be checked for aggregates
* to be attached to result_plan->aggs (see planner.c:union_planner() )
*/
foreach(t,((List *)((SubLink *)((SubPlan *)
((Expr *)clause)->oper)->sublink)->lefthand))
{
agg_list =
nconc(agg_list,
check_having_qual_for_aggs(lfirst(t),
subplanTargetList, groupClause));
}
/*
* Only the lefthand side of the sublink has to be checked for
* aggregates to be attached to result_plan->aggs (see
* planner.c:union_planner() )
*/
foreach(t, ((List *) ((SubLink *) ((SubPlan *)
((Expr *) clause)->oper)->sublink)->lefthand))
{
agg_list =
nconc(agg_list,
check_having_qual_for_aggs(lfirst(t),
subplanTargetList, groupClause));
/* The first argument of ...->oper has also to be checked */
{
List *tmp_ptr;
foreach(tmp_ptr, ((SubLink *)((SubPlan *)
((Expr *)clause)->oper)->sublink)->oper)
{
agg_list =
nconc(agg_list,
check_having_qual_for_aggs((Node *)lfirst(((Expr *)
lfirst(tmp_ptr))->args),
subplanTargetList, groupClause));
}
}
/* All arguments to the Sublink node are attributes from outside used within
* the sublink. Here we have to check that only attributes that is grouped for
* are used! */
foreach(t,((Expr *)clause)->args)
{
contained_in_group_clause = 0;
/*
* All arguments to the Sublink node are attributes from outside
* used within the sublink. Here we have to check that only
* attributes that is grouped for are used!
*/
foreach(t, ((Expr *) clause)->args)
{
contained_in_group_clause = 0;
foreach(l1, groupClause)
{
if (tlist_member(lfirst(t), lcons(((GroupClause *) lfirst(l1))->entry, NIL)) !=
NULL)
contained_in_group_clause = 1;
}
/*
* If the use of the attribute is allowed (i.e. it is in the
* groupClause) we have to adjust the varnos and varattnos
*/
if (contained_in_group_clause)
{
agg_list =
nconc(agg_list,
check_having_qual_for_aggs(lfirst(t),
subplanTargetList, groupClause));
}
else
{
elog(ERROR, "You must group by the attribute used from outside!");
return NIL;
}
}
return agg_list;
}
foreach(l1,groupClause)
{
if (tlist_member(lfirst(t),lcons(((GroupClause *)lfirst(l1))->entry,NIL)) !=
NULL)
{
contained_in_group_clause=1;
}
}
/* If the use of the attribute is allowed (i.e. it is in the groupClause)
* we have to adjust the varnos and varattnos */
if (contained_in_group_clause)
{
agg_list =
nconc(agg_list,
check_having_qual_for_aggs(lfirst(t),
subplanTargetList, groupClause));
}
else
{
elog(ERROR,"You must group by the attribute used from outside!");
return NIL;
}
}
return agg_list;
}
else
{
/*
* Ooops! we can not handle that!
*/
elog(ERROR, "check_having_qual_for_aggs: Can not handle this having_qual! %d\n",
nodeTag(clause));
return NIL;
}
{
/*
* Ooops! we can not handle that!
*/
elog(ERROR, "check_having_qual_for_aggs: Can not handle this having_qual! %d\n",
nodeTag(clause));
return NIL;
}
}
/***S*H***/ /* End */

14
src/backend/optimizer/plan/subselect.c
View File

@ -405,20 +405,6 @@ SS_process_sublinks(Node *expr)
SS_process_sublinks((Node *) ((Expr *) expr)->args);
else if (IsA(expr, SubLink))/* got it! */
{
/*
* Hack to make sure expr->oper->args points to the same VAR node
* as expr->lefthand does. Needed for subselects in the havingQual
* when used on views. Otherwise aggregate functions will fail
* later on (at execution time!) Reason: The rewite System makes
* several copies of the VAR nodes and in this case it should not
* do so :-(
*/
if (((SubLink *) expr)->lefthand != NULL)
{
lfirst(((Expr *) lfirst(((SubLink *) expr)->oper))->args) =
lfirst(((SubLink *) expr)->lefthand);
}
expr = _make_subplan((SubLink *) expr);
}

117
src/backend/parser/analyze.c
View File

@ -5,7 +5,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: analyze.c,v 1.91 1998/12/14 06:50:32 scrappy Exp $
* $Id: analyze.c,v 1.92 1999/01/18 00:09:49 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -26,6 +26,11 @@
#include "parser/parse_node.h"
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
/***S*I***/
#include "parser/parse_expr.h"
#include "catalog/pg_type.h"
#include "parse.h"
#include "utils/builtins.h"
#include "utils/mcxt.h"
@ -383,8 +388,13 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
* The INSERT INTO ... SELECT ... could have a UNION in child, so
* unionClause may be false
*/
qry->unionall = stmt->unionall;
qry->unionClause = transformUnionClause(stmt->unionClause, qry->targetList);
qry->unionall = stmt->unionall;
/***S*I***/
/* Just hand through the unionClause and intersectClause.
* We will handle it in the function Except_Intersect_Rewrite() */
qry->unionClause = stmt->unionClause;
qry->intersectClause = stmt->intersectClause;
/*
* If there is a havingQual but there are no aggregates, then there is
@ -942,7 +952,12 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
* unionClause may be false
*/
qry->unionall = stmt->unionall;
qry->unionClause = transformUnionClause(stmt->unionClause, qry->targetList);
/***S*I***/
/* Just hand through the unionClause and intersectClause.
* We will handle it in the function Except_Intersect_Rewrite() */
qry->unionClause = stmt->unionClause;
qry->intersectClause = stmt->intersectClause;
/*
* If there is a havingQual but there are no aggregates, then there is
@ -1012,3 +1027,97 @@ transformCursorStmt(ParseState *pstate, SelectStmt *stmt)
return qry;
}
/***S*I***/
/* This function steps through the tree
* built up by the select_w_o_sort rule
* and builds a list of all SelectStmt Nodes found
* The built up list is handed back in **select_list.
* If one of the SelectStmt Nodes has the 'unionall' flag
* set to true *unionall_present hands back 'true' */
void
create_select_list(Node *ptr, List **select_list, bool *unionall_present)
{
if(IsA(ptr, SelectStmt)) {
*select_list = lappend(*select_list, ptr);
if(((SelectStmt *)ptr)->unionall == TRUE) *unionall_present = TRUE;
return;
}
/* Recursively call for all arguments. A NOT expr has no lexpr! */
if (((A_Expr *)ptr)->lexpr != NULL)
create_select_list(((A_Expr *)ptr)->lexpr, select_list, unionall_present);
create_select_list(((A_Expr *)ptr)->rexpr, select_list, unionall_present);
}
/* Changes the A_Expr Nodes to Expr Nodes and exchanges ANDs and ORs.
* The reason for the exchange is easy: We implement INTERSECTs and EXCEPTs
* by rewriting these queries to semantically equivalent queries that use
* IN and NOT IN subselects. To be able to use all three operations
* (UNIONs INTERSECTs and EXCEPTs) in one complex query we have to
* translate the queries into Disjunctive Normal Form (DNF). Unfortunately
* there is no function 'dnfify' but there is a function 'cnfify'
* which produces DNF when we exchange ANDs and ORs before calling
* 'cnfify' and exchange them back in the result.
*
* If an EXCEPT or INTERSECT is present *intersect_present
* hands back 'true' */
Node *A_Expr_to_Expr(Node *ptr, bool *intersect_present)
{
Node *result;
switch(nodeTag(ptr))
{
case T_A_Expr:
{
A_Expr *a = (A_Expr *)ptr;
switch (a->oper)
{
case AND:
{
Expr *expr = makeNode(Expr);
Node *lexpr = A_Expr_to_Expr(((A_Expr *)ptr)->lexpr, intersect_present);
Node *rexpr = A_Expr_to_Expr(((A_Expr *)ptr)->rexpr, intersect_present);
*intersect_present = TRUE;
expr->typeOid = BOOLOID;
expr->opType = OR_EXPR;
expr->args = makeList(lexpr, rexpr, -1);
result = (Node *) expr;
break;
}
case OR:
{
Expr *expr = makeNode(Expr);
Node *lexpr = A_Expr_to_Expr(((A_Expr *)ptr)->lexpr, intersect_present);
Node *rexpr = A_Expr_to_Expr(((A_Expr *)ptr)->rexpr, intersect_present);
expr->typeOid = BOOLOID;
expr->opType = AND_EXPR;
expr->args = makeList(lexpr, rexpr, -1);
result = (Node *) expr;
break;
}
case NOT:
{
Expr *expr = makeNode(Expr);
Node *rexpr = A_Expr_to_Expr(((A_Expr *)ptr)->rexpr, intersect_present);
expr->typeOid = BOOLOID;
expr->opType = NOT_EXPR;
expr->args = makeList(rexpr, -1);
result = (Node *) expr;
break;
}
}
break;
}
default:
{
result = ptr;
}
}
return result;
}

368
src/backend/parser/gram.y
View File

@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.42 1999/01/05 15:46:25 vadim Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.43 1999/01/18 00:09:51 momjian Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -47,6 +47,7 @@
#include "access/xact.h"
#include "storage/lmgr.h"
#include "utils/numeric.h"
#include "parser/analyze.h"
#ifdef MULTIBYTE
#include "mb/pg_wchar.h"
@ -128,9 +129,9 @@ 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, CursorStmt, SubSelect, SubUnion,
UpdateStmt, InsertStmt, SelectStmt, NotifyStmt, DeleteStmt, ClusterStmt,
ExplainStmt, VariableSetStmt, VariableShowStmt, VariableResetStmt,
CreatedbStmt, DestroydbStmt, VacuumStmt, CursorStmt, SubSelect,
UpdateStmt, InsertStmt, select_w_o_sort, SelectStmt, NotifyStmt, DeleteStmt,
ClusterStmt, ExplainStmt, VariableSetStmt, VariableShowStmt, VariableResetStmt,
CreateUserStmt, AlterUserStmt, DropUserStmt
%type <str> opt_database1, opt_database2, location, encoding
@ -174,7 +175,7 @@ Oid param_type(int t); /* used in parse_expr.c */
%type <boolean> TriggerForOpt, TriggerForType
%type <list> union_clause, select_list, for_update_clause
%type <list> for_update_clause
%type <list> join_list
%type <joinusing>
join_using
@ -271,11 +272,11 @@ Oid param_type(int t); /* used in parse_expr.c */
CONSTRAINT, CREATE, CROSS, CURRENT, CURRENT_DATE, CURRENT_TIME,
CURRENT_TIMESTAMP, CURRENT_USER, CURSOR,
DAY_P, DECIMAL, DECLARE, DEFAULT, DELETE, DESC, DISTINCT, DOUBLE, DROP,
ELSE, END_TRANS, EXECUTE, EXISTS, EXTRACT,
ELSE, END_TRANS, EXCEPT, EXECUTE, EXISTS, EXTRACT,
FALSE_P, FETCH, FLOAT, FOR, FOREIGN, FROM, FULL,
GRANT, GROUP, HAVING, HOUR_P,
IN, INNER_P, INSENSITIVE, INSERT, INTERVAL, INTO, IS, ISOLATION,
JOIN, KEY, LANGUAGE, LEADING, LEFT, LEVEL, LIKE, LOCAL,
IN, INNER_P, INSENSITIVE, INSERT, INTERSECT, INTERVAL, INTO, IS,
ISOLATION, JOIN, KEY, LANGUAGE, LEADING, LEFT, LEVEL, LIKE, LOCAL,
MATCH, MINUTE_P, MONTH_P, NAMES,
NATIONAL, NATURAL, NCHAR, NEXT, NO, NOT, NULLIF, NULL_P, NUMERIC,
OF, ON, ONLY, OPTION, OR, ORDER, OUTER_P,
@ -343,7 +344,7 @@ Oid param_type(int t); /* used in parse_expr.c */
%left '.'
%left '[' ']'
%nonassoc TYPECAST
%left UNION
%left UNION INTERSECT EXCEPT
%%
stmtblock: stmtmulti
@ -354,8 +355,13 @@ stmtblock: stmtmulti
stmtmulti: stmtmulti stmt ';'
{ $$ = lappend($1, $2); }
| stmtmulti stmt
{ $$ = lappend($1, $2); }
/***S*I***/
/* We comment the next rule because it seems to be redundant
* and produces 16 shift/reduce conflicts with the new SelectStmt rule
* needed for EXCEPT and INTERSECTS. So far I did not notice any
* violations by removing the rule! */
/* | stmtmulti stmt
{ $$ = lappend($1, $2); } */
| stmt ';'
{ $$ = lcons($1,NIL); }
;
@ -2062,7 +2068,10 @@ RuleStmt: CREATE RULE name AS
OptStmtList: NOTHING { $$ = NIL; }
| OptimizableStmt { $$ = lcons($1, NIL); }
| '[' OptStmtBlock ']' { $$ = $2; }
| '(' OptStmtBlock ')' { $$ = $2; }
/***S*I*D***/
/* We comment this out because it produces a shift / reduce conflict
* with the select_w_o_sort rule */
/* | '(' OptStmtBlock ')' { $$ = $2; } */
;
OptStmtBlock: OptStmtMulti
@ -2073,8 +2082,13 @@ OptStmtBlock: OptStmtMulti
OptStmtMulti: OptStmtMulti OptimizableStmt ';'
{ $$ = lappend($1, $2); }
| OptStmtMulti OptimizableStmt
{ $$ = lappend($1, $2); }
/***S*I***/
/* We comment the next rule because it seems to be redundant
* and produces 16 shift/reduce conflicts with the new SelectStmt rule
* needed for EXCEPT and INTERSECT. So far I did not notice any
* violations by removing the rule! */
/* | OptStmtMulti OptimizableStmt
{ $$ = lappend($1, $2); } */
| OptimizableStmt ';'
{ $$ = lcons($1, NIL); }
;
@ -2426,17 +2440,23 @@ OptimizableStmt: SelectStmt
*
*****************************************************************************/
InsertStmt: INSERT INTO relation_name opt_column_list insert_rest
/***S*I***/
/* This rule used 'opt_column_list' between 'relation_name' and 'insert_rest'
* originally. When the second rule of 'insert_rest' was changed to use
* the new 'SelectStmt' rule (for INTERSECT and EXCEPT) it produced a shift/reduce
* conflict. So I just changed the rules 'InsertStmt' and 'insert_rest' to accept
* the same statements without any shift/reduce conflicts */
InsertStmt: INSERT INTO relation_name insert_rest
{
$5->relname = $3;
$5->cols = $4;
$$ = (Node *)$5;
$4->relname = $3;
$$ = (Node *)$4;
}
;
insert_rest: VALUES '(' res_target_list2 ')'
{
$$ = makeNode(InsertStmt);
$$->cols = NULL;
$$->unique = NULL;
$$->targetList = $3;
$$->fromClause = NIL;
@ -2455,20 +2475,57 @@ insert_rest: VALUES '(' res_target_list2 ')'
$$->groupClause = NIL;
$$->havingClause = NULL;
$$->unionClause = NIL;
/***S*I***/
$$->intersectClause = NIL;
}
| SELECT opt_unique res_target_list2
from_clause where_clause
group_clause having_clause
union_clause
/***S*I***/
/* We want the full power of SelectStatements including INTERSECT and EXCEPT
* for insertion */
| SelectStmt
{
SelectStmt *n;
n = (SelectStmt *)$1;
$$ = makeNode(InsertStmt);
$$->cols = NULL;
$$->unique = n->unique;
$$->targetList = n->targetList;
$$->fromClause = n->fromClause;
$$->whereClause = n->whereClause;
$$->groupClause = n->groupClause;
$$->havingClause = n->havingClause;
$$->unionClause = n->unionClause;
$$->intersectClause = n->intersectClause;
}
| '(' columnList ')' VALUES '(' res_target_list2 ')'
{
$$ = makeNode(InsertStmt);
$$->unique = $2;
$$->targetList = $3;
$$->fromClause = $4;
$$->whereClause = $5;
$$->groupClause = $6;
$$->havingClause = $7;
$$->unionClause = $8;
$$->cols = $2;
$$->unique = NULL;
$$->targetList = $6;
$$->fromClause = NIL;
$$->whereClause = NULL;
$$->groupClause = NIL;
$$->havingClause = NULL;
$$->unionClause = NIL;
/***S*I***/
$$->intersectClause = NIL;
}
| '(' columnList ')' SelectStmt
{
SelectStmt *n;
n = (SelectStmt *)$4;
$$ = makeNode(InsertStmt);
$$->cols = $2;
$$->unique = n->unique;
$$->targetList = n->targetList;
$$->fromClause = n->fromClause;
$$->whereClause = n->whereClause;
$$->groupClause = n->groupClause;
$$->havingClause = n->havingClause;
$$->unionClause = n->unionClause;
$$->intersectClause = n->intersectClause;
}
;
@ -2610,18 +2667,15 @@ UpdateStmt: UPDATE relation_name
* CURSOR STATEMENTS
*
*****************************************************************************/
CursorStmt: DECLARE name opt_cursor CURSOR FOR
SELECT opt_unique res_target_list2
from_clause where_clause
group_clause having_clause
union_clause sort_clause
cursor_clause
{
SelectStmt *n = makeNode(SelectStmt);
/* from PORTAL name */
/*
* 15 august 1991 -- since 3.0 postgres does locking
/***S*I***/
CursorStmt: DECLARE name opt_cursor CURSOR FOR SelectStmt cursor_clause
{
SelectStmt *n;
n= (SelectStmt *)$6;
/* from PORTAL name */
/*
* 15 august 1991 -- since 3.0 postgres does locking
* right, we discovered that portals were violating
* locking protocol. portal locks cannot span xacts.
* as a short-term fix, we installed the check here.
@ -2632,14 +2686,6 @@ CursorStmt: DECLARE name opt_cursor CURSOR FOR
n->portalname = $2;
n->binary = $3;
n->unique = $7;
n->targetList = $8;
n->fromClause = $9;
n->whereClause = $10;
n->groupClause = $11;
n->havingClause = $12;
n->unionClause = $13;
n->sortClause = $14;
$$ = (Node *)n;
}
;
@ -2675,88 +2721,164 @@ opt_of: OF columnList
* SELECT STATEMENTS
*
*****************************************************************************/
/***S*I***/
/* The new 'SelectStmt' rule adapted for the optional use of INTERSECT EXCEPT and UNION
* accepts the use of '(' and ')' to select an order of set operations.
*
* The rule returns a SelectStmt Node having the set operations attached to
* unionClause and intersectClause (NIL if no set operations were present) */
SelectStmt: select_w_o_sort sort_clause for_update_clause
{
/* There were no set operations, so just attach the sortClause */
if IsA($1, SelectStmt)
{
SelectStmt *n = (SelectStmt *)$1;
n->sortClause = $2;
n->forUpdate = $3;
$$ = (Node *)n;
}
/* There were set operations: The root of the operator tree
* is delivered by $1 but we cannot hand back an A_Expr Node.
* So we search for the leftmost 'SelectStmt' in the operator
* tree $1 (which is the first Select Statement in the query
* typed in by the user or where ever it came from).
*
* Then we attach the whole operator tree to 'intersectClause',
* and a list of all 'SelectStmt' Nodes to 'unionClause' and
* hand back the leftmost 'SelectStmt' Node. (We do it this way
* because the following functions (e.g. parse_analyze etc.)
* excpect a SelectStmt node and not an operator tree! The whole
* tree attached to 'intersectClause' won't be touched by
* parse_analyze() etc. until the function
* Except_Intersect_Rewrite() (in rewriteHandler.c) which performs
* the necessary steps to be able create a plan!) */
else
{
List *select_list = NIL;
SelectStmt *first_select;
Node *op = (Node *) $1;
bool intersect_present = FALSE, unionall_present = FALSE;
SelectStmt: SELECT opt_unique res_target_list2
/* Take the operator tree as an argument and
* create a list of all SelectStmt Nodes found in the tree.
*
* If one of the SelectStmt Nodes has the 'unionall' flag
* set to true the 'unionall_present' flag is also set to
* true */
create_select_list((Node *)op, &select_list, &unionall_present);
/* Replace all the A_Expr Nodes in the operator tree by
* Expr Nodes.
*
* If an INTERSECT or an EXCEPT is present, the
* 'intersect_present' flag is set to true */
op = A_Expr_to_Expr(op, &intersect_present);
/* If both flags are set to true we have a UNION ALL
* statement mixed up with INTERSECT or EXCEPT
* which can not be handled at the moment */
if (intersect_present && unionall_present)
{
elog(ERROR,"UNION ALL not allowed in mixed set operations!");
}
/* Get the leftmost SeletStmt Node (which automatically
* represents the first Select Statement of the query!) */
first_select = (SelectStmt *)lfirst(select_list);
/* Attach the list of all SeletStmt Nodes to unionClause */
first_select->unionClause = select_list;
/* Attach the whole operator tree to intersectClause */
first_select->intersectClause = (List *) op;
/* finally attach the sort clause */
first_select->sortClause = $2;
first_select>forUpdate = $3;
$$ = (Node *)first_select;
}
if ((SelectStmt *)$$)->forUpdate != NULL)
{
SelectStmt *n = (SelectStmt *)$1;
if (n->unionClause != NULL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with UNION clause");
if (n->unique != NULL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with DISTINCT clause");
if (n->groupClause != NULL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with GROUP BY clause");
if (n->havingClause != NULL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with HAVING clause");
}
}
;
/***S*I***/
/* This rule parses Select statements including UNION INTERSECT and EXCEPT.
* '(' and ')' can be used to specify the order of the operations
* (UNION EXCEPT INTERSECT). Without the use of '(' and ')' we want the
* operations to be left associative.
*
* The sort_clause is not handled here!
*
* The rule builds up an operator tree using A_Expr Nodes. AND Nodes represent
* INTERSECTs OR Nodes represent UNIONs and AND NOT nodes represent EXCEPTs.
* The SelectStatements to be connected are the left and right arguments to
* the A_Expr Nodes.
* If no set operations show up in the query the tree consists only of one
* SelectStmt Node */
select_w_o_sort: '(' select_w_o_sort ')'
{
$$ = $2;
}
| SubSelect
{
$$ = $1;
}
| select_w_o_sort EXCEPT select_w_o_sort
{
$$ = (Node *)makeA_Expr(AND,NULL,$1,
makeA_Expr(NOT,NULL,NULL,$3));
}
| select_w_o_sort UNION opt_union select_w_o_sort
{
if (IsA($4, SelectStmt))
{
SelectStmt *n = (SelectStmt *)$4;
n->unionall = $3;
}
$$ = (Node *)makeA_Expr(OR,NULL,$1,$4);
}
| select_w_o_sort INTERSECT select_w_o_sort
{
$$ = (Node *)makeA_Expr(AND,NULL,$1,$3);
}
;
/***S*I***/
SubSelect: SELECT opt_unique res_target_list2
result from_clause where_clause
group_clause having_clause
union_clause sort_clause for_update_clause
{
SelectStmt *n = makeNode(SelectStmt);
n->unique = $2;
n->targetList = $3;
n->into = $4;
n->fromClause = $5;
n->whereClause = $6;
n->groupClause = $7;
n->havingClause = $8;
n->unionClause = $9;
n->sortClause = $10;
n->forUpdate = $11;
if (n->forUpdate != NULL)
{
if (n->unionClause != NULL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with UNION clause");
if (n->unique != NULL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with DISTINCT clause");
if (n->groupClause != NULL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with GROUP BY clause");
if (n->havingClause != NULL)
elog(ERROR, "SELECT FOR UPDATE is not allowed with HAVING clause");
}
else
$$ = (Node *)n;
}
;
SubSelect: SELECT opt_unique res_target_list2
from_clause where_clause
group_clause having_clause
union_clause
{
SelectStmt *n = makeNode(SelectStmt);
n->unique = $2;
n->targetList = $3;
n->fromClause = $4;
n->whereClause = $5;
n->groupClause = $6;
n->havingClause = $7;
n->unionClause = $8;
$$ = (Node *)n;
}
;
union_clause: UNION opt_union select_list
{
SelectStmt *n = (SelectStmt *)lfirst($3);
n->unionall = $2;
$$ = $3;
}
| /*EMPTY*/
{ $$ = NIL; }
;
select_list: select_list UNION opt_union SubUnion
{
SelectStmt *n = (SelectStmt *)$4;
n->unionall = $3;
$$ = lappend($1, $4);
}
| SubUnion
{ $$ = lcons($1, NIL); }
;
SubUnion: SELECT opt_unique res_target_list2
from_clause where_clause
group_clause having_clause
{
SelectStmt *n = makeNode(SelectStmt);
n->unique = $2;
n->unionall = FALSE;
n->targetList = $3;
n->fromClause = $4;
n->whereClause = $5;
n->groupClause = $6;
n->havingClause = $7;
/***S*I***/
/* This is new: Subselects support the INTO clause
* which allows queries that are not part of the
* SQL92 standard and should not be formulated!
* We need it for INTERSECT and EXCEPT and I did not
* want to create a new rule 'SubSelect1' including the
* feature. If it makes troubles we will have to add
* a new rule and change this to prevent INTOs in
* Subselects again */
n->into = $4;
n->fromClause = $5;
n->whereClause = $6;
n->groupClause = $7;
n->havingClause = $8;
$$ = (Node *)n;
}
;

8
src/backend/parser/keywords.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.50 1998/12/18 09:10:34 vadim Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.51 1999/01/18 00:09:53 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -93,6 +93,9 @@ static ScanKeyword ScanKeywords[] = {
{"else", ELSE},
{"encoding", ENCODING},
{"end", END_TRANS},
/***S*I***/
{"except", EXCEPT},
{"execute", EXECUTE},
{"exists", EXISTS},
{"explain", EXPLAIN},
@ -120,6 +123,9 @@ static ScanKeyword ScanKeywords[] = {
{"insensitive", INSENSITIVE},
{"insert", INSERT},
{"instead", INSTEAD},
/***S*I***/
{"intersect", INTERSECT},
{"interval", INTERVAL},
{"into", INTO},
{"is", IS},

402
src/backend/rewrite/rewriteHandler.c
View File

@ -6,7 +6,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.27 1998/12/14 00:02:16 thomas Exp $
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.28 1999/01/18 00:09:54 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -24,6 +24,13 @@
#include "parser/parse_relation.h"
#include "nodes/parsenodes.h"
/***S*I***/
#include "parser/parse_node.h"
#include "parser/parse_target.h"
#include "parser/analyze.h"
#include "optimizer/prep.h"
#include "rewrite/rewriteSupport.h"
#include "rewrite/rewriteHandler.h"
#include "rewrite/rewriteManip.h"
@ -1661,7 +1668,8 @@ apply_RIR_view(Node **nodePtr, int rt_index, RangeTblEntry *rte, List *tlist, in
case T_SubLink:
{
SubLink *sub = (SubLink *)node;
SubLink *sub = (SubLink *)node;
List *tmp_lefthand, *tmp_oper;
apply_RIR_view(
(Node **)(&(sub->lefthand)),
@ -1678,6 +1686,15 @@ apply_RIR_view(Node **nodePtr, int rt_index, RangeTblEntry *rte, List *tlist, in
tlist,
modified,
sublevels_up + 1);
/***S*I***/
tmp_lefthand = sub->lefthand;
foreach(tmp_oper, sub->oper)
{
lfirst(((Expr *) lfirst(tmp_oper))->args) =
lfirst(tmp_lefthand);
tmp_lefthand = lnext(tmp_lefthand);
}
}
break;
@ -2614,8 +2631,387 @@ QueryRewrite(Query *parsetree)
query = (Query *)lfirst(l);
results = lappend(results, fireRIRrules(query));
}
return results;
}
/***S*I***/
/* This function takes two targetlists as arguments and checks if the targetlists are compatible
* (i.e. both select for the same number of attributes and the types are compatible
*/
void check_targetlists_are_compatible(List *prev_target, List *current_target)
{
List *next_target;
if (length(prev_target) !=
length(current_target))
elog(ERROR,"Each UNION | EXCEPT | INTERSECT query must have the same number of columns.");
foreach(next_target, current_target)
{
Oid itype;
Oid otype;
otype = ((TargetEntry *) lfirst(prev_target))->resdom->restype;
itype = ((TargetEntry *) lfirst(next_target))->resdom->restype;
/* one or both is a NULL column? then don't convert... */
if (otype == InvalidOid)
{
/* propagate a known type forward, if available */
if (itype != InvalidOid)
((TargetEntry *) lfirst(prev_target))->resdom->restype = itype;
#if FALSE
else
{
((TargetEntry *) lfirst(prev_target))->resdom->restype = UNKNOWNOID;
((TargetEntry *) lfirst(next_target))->resdom->restype = UNKNOWNOID;
}
#endif
}
else if (itype == InvalidOid)
{
}
/* they don't match in type? then convert... */
else if (itype != otype)
{
Node *expr;
expr = ((TargetEntry *) lfirst(next_target))->expr;
expr = CoerceTargetExpr(NULL, expr, itype, otype);
if (expr == NULL)
{
elog(ERROR, "Unable to transform %s to %s"
"\n\tEach UNION | EXCEPT | INTERSECT clause must have compatible target types",
typeidTypeName(itype),
typeidTypeName(otype));
}
((TargetEntry *) lfirst(next_target))->expr = expr;
((TargetEntry *) lfirst(next_target))->resdom->restype = otype;
}
/* both are UNKNOWN? then evaluate as text... */
else if (itype == UNKNOWNOID)
{
((TargetEntry *) lfirst(next_target))->resdom->restype = TEXTOID;
((TargetEntry *) lfirst(prev_target))->resdom->restype = TEXTOID;
}
prev_target = lnext(prev_target);
}
}
/***S*I***/
/* Rewrites UNION INTERSECT and EXCEPT queries to semantiacally equivalent
* queries that use IN and NOT IN subselects.
*
* The operator tree is attached to 'intersectClause' (see rule
* 'SelectStmt' in gram.y) of the 'parsetree' given as an
* argument. First we remember some clauses (the sortClause, the
* unique flag etc.) Then we translate the operator tree to DNF
* (disjunctive normal form) by 'cnfify'. (Note that 'cnfify' produces
* CNF but as we exchanged ANDs with ORs in function A_Expr_to_Expr()
* earlier we get DNF after exchanging ANDs and ORs again in the
* result.) Now we create a new query by evaluating the new operator
* tree which is in DNF now. For every AND we create an entry in the
* union list and for every OR we create an IN subselect. (NOT IN
* subselects are created for OR NOT nodes). The first entry of the
* union list is handed back but before that the remembered clauses
* (sortClause etc) are attached to the new top Node (Note that the
* new top Node can differ from the parsetree given as argument because of
* the translation to DNF. That's why we have to remember the sortClause or
* unique flag!) */
Query *
Except_Intersect_Rewrite (Query *parsetree)
{
SubLink *n;
Query *result, *intersect_node;
List *elist, *intersect_list = NIL, *intersect, *intersectClause;
List *union_list = NIL, *sortClause;
List *left_expr, *right_expr, *resnames = NIL;
char *op, *uniqueFlag, *into;
bool isBinary, isPortal;
CmdType commandType = CMD_SELECT;
List *rtable_insert = NIL;
List *prev_target = NIL;
/* Remember the Resnames of the given parsetree's targetlist
* (these are the resnames of the first Select Statement of
* the query formulated by the user and he wants the columns
* named by these strings. The transformation to DNF can
* cause another Select Statment to be the top one which
* uses other names for its columns. Therefore we remeber
* the original names and attach them to the targetlist
* of the new topmost Node at the end of this function */
foreach(elist, parsetree->targetList)
{
TargetEntry *tent = (TargetEntry *)lfirst(elist);
resnames = lappend(resnames, tent->resdom->resname);
}
/* If the Statement is an INSERT INTO ... (SELECT...) statement
* using UNIONs, INTERSECTs or EXCEPTs and the transformation
* to DNF makes another Node to the top node we have to transform
* the new top node to an INSERT node and the original INSERT node
* to a SELECT node */
if (parsetree->commandType == CMD_INSERT)
{
parsetree->commandType = CMD_SELECT;
commandType = CMD_INSERT;
parsetree->resultRelation = 0;
/* The result relation ( = the one to insert into) has to be
* attached to the rtable list of the new top node */
rtable_insert = nth(length(parsetree->rtable) - 1, parsetree->rtable);
}
/* Save some items, to be able to attach them to the resulting top node
* at the end of the function */
sortClause = parsetree->sortClause;
uniqueFlag = parsetree->uniqueFlag;
into = parsetree->into;
isBinary = parsetree->isBinary;
isPortal = parsetree->isPortal;
/* The operator tree attached to parsetree->intersectClause is still 'raw'
* ( = the leaf nodes are still SelectStmt nodes instead of Query nodes)
* So step through the tree and transform the nodes using parse_analyze().
*
* The parsetree (given as an argument to
* Except_Intersect_Rewrite()) has already been transformed and
* transforming it again would cause troubles. So we give the 'raw'
* version (of the cooked parsetree) to the function to
* prevent an additional transformation. Instead we hand back the
* 'cooked' version also given as an argument to
* intersect_tree_analyze() */
intersectClause =
(List *)intersect_tree_analyze((Node *)parsetree->intersectClause,
(Node *)lfirst(parsetree->unionClause),
(Node *)parsetree);
/* intersectClause is no longer needed so set it to NIL */
parsetree->intersectClause = NIL;
/* unionClause will be needed later on but the list it delivered
* is no longer needed, so set it to NIL */
parsetree->unionClause = NIL;
/* Transform the operator tree to DNF (remember ANDs and ORs have been exchanged,
* that's why we get DNF by using cnfify)
*
* After the call, explicit ANDs are removed and all AND operands
* are simply items in the intersectClause list */
intersectClause = cnfify((Expr *)intersectClause, true);
/* For every entry of the intersectClause list we generate one entry in
* the union_list */
foreach(intersect, intersectClause)
{
/* for every OR we create an IN subselect and for every OR NOT
* we create a NOT IN subselect, so first extract all the Select
* Query nodes from the tree (that contains only OR or OR NOTs
* any more because we did a transformation to DNF
*
* There must be at least one node that is not negated
* (i.e. just OR and not OR NOT) and this node will be the first
* in the list returned */
intersect_list = NIL;
create_list((Node *)lfirst(intersect), &intersect_list);
/* This one will become the Select Query node, all other
* nodes are transformed into subselects under this node! */
intersect_node = (Query *)lfirst(intersect_list);
intersect_list = lnext(intersect_list);
/* Check if all Select Statements use the same number of attributes and
* if all corresponding attributes are of the same type */
if (prev_target)
check_targetlists_are_compatible(prev_target, intersect_node->targetList);
prev_target = intersect_node->targetList;
/* End of check for corresponding targetlists */
/* Transform all nodes remaining into subselects and add them to
* the qualifications of the Select Query node */
while(intersect_list != NIL) {
n = makeNode(SubLink);
/* Here we got an OR so transform it to an IN subselect */
if(IsA(lfirst(intersect_list), Query))
{
/* Check if all Select Statements use the same number of attributes and
* if all corresponding attributes are of the same type */
check_targetlists_are_compatible(prev_target,
((Query *)lfirst(intersect_list))->targetList);
/* End of check for corresponding targetlists */
n->subselect = lfirst(intersect_list);
op = "=";
n->subLinkType = ANY_SUBLINK;
n->useor = false;
}
/* Here we got an OR NOT node so transform it to a NOT IN subselect */
else
{
/* Check if all Select Statements use the same number of attributes and
* if all corresponding attributes are of the same type */
check_targetlists_are_compatible(prev_target,
((Query *)lfirst(((Expr *)lfirst(intersect_list))->args))->targetList);
/* End of check for corresponding targetlists */
n->subselect = (Node *)lfirst(((Expr *)lfirst(intersect_list))->args);
op = "<>";
n->subLinkType = ALL_SUBLINK;
n->useor = true;
}
/* Prepare the lefthand side of the Sublinks: All the entries of the
* targetlist must be (IN) or must not be (NOT IN) the subselect */
foreach(elist, intersect_node->targetList)
{
Node *expr = lfirst(elist);
TargetEntry *tent = (TargetEntry *)expr;
n->lefthand = lappend(n->lefthand, tent->expr);
}
/* The first arguments of oper also have to be created for the
* sublink (they are the same as the lefthand side!) */
left_expr = n->lefthand;
right_expr = ((Query *)(n->subselect))->targetList;
foreach(elist, left_expr)
{
Node *lexpr = lfirst(elist);
Node *rexpr = lfirst(right_expr);
TargetEntry *tent = (TargetEntry *) rexpr;
Expr *op_expr;
op_expr = make_op(op, lexpr, tent->expr);
n->oper = lappend(n->oper, op_expr);
right_expr = lnext(right_expr);
}
/* If the Select Query node has aggregates in use
* add all the subselects to the HAVING qual else to
* the WHERE qual */
if(intersect_node->hasAggs == false) {
AddQual(intersect_node, (Node *)n);
}
else {
AddHavingQual(intersect_node, (Node *)n);
}
/* Now we got sublinks */
intersect_node->hasSubLinks = true;
intersect_list = lnext(intersect_list);
}
intersect_node->intersectClause = NIL;
union_list = lappend(union_list, intersect_node);
}
/* The first entry to union_list is our new top node */
result = (Query *)lfirst(union_list);
/* attach the rest to unionClause */
result->unionClause = lnext(union_list);
/* Attach all the items remembered in the beginning of the function */
result->sortClause = sortClause;
result->uniqueFlag = uniqueFlag;
result->into = into;
result->isPortal = isPortal;
result->isBinary = isBinary;
/* The relation to insert into is attached to the range table
* of the new top node */
if (commandType == CMD_INSERT)
{
result->rtable = lappend(result->rtable, rtable_insert);
result->resultRelation = length(result->rtable);
result->commandType = commandType;
}
/* The resnames of the originally first SelectStatement are
* attached to the new first SelectStatement */
foreach(elist, result->targetList)
{
TargetEntry *tent = (TargetEntry *)lfirst(elist);
tent->resdom->resname = lfirst(resnames);
resnames = lnext(resnames);
}
return result;
}
/* Create a list of nodes that are either Query nodes of NOT Expr
* nodes followed by a Query node. The tree given in ptr contains at
* least one non negated Query node. This node is attached to the
* beginning of the list */
void create_list(Node *ptr, List **intersect_list)
{
List *arg;
if(IsA(ptr,Query))
{
/* The non negated node is attached at the beginning (lcons) */
*intersect_list = lcons(ptr, *intersect_list);
return;
}
if(IsA(ptr,Expr))
{
if(((Expr *)ptr)->opType == NOT_EXPR)
{
/* negated nodes are appended to the end (lappend) */
*intersect_list = lappend(*intersect_list, ptr);
return;
}
else
{
foreach(arg, ((Expr *)ptr)->args)
{
create_list(lfirst(arg), intersect_list);
}
return;
}
return;
}
}
/* The nodes given in 'tree' are still 'raw' so 'cook' them using parse_analyze().
* The node given in first_select has already been cooked, so don't transform
* it again but return a pointer to the previously cooked version given in 'parsetree'
* instead. */
Node *intersect_tree_analyze(Node *tree, Node *first_select, Node *parsetree)
{
Node *result = (Node *)NIL;
List *arg;
if(IsA(tree, SelectStmt))
{
QueryTreeList *qtree;
/* If we get to the tree given in first_select return
* parsetree instead of performing parse_analyze() */
if(tree == first_select){
result = parsetree;
}
else {
/* transform the 'raw' nodes to 'cooked' Query nodes */
qtree = parse_analyze(lcons(tree, NIL), NULL);
result = (Node *)qtree->qtrees[0];
}
}
if(IsA(tree,Expr))
{
/* Call recursively for every argument of the node */
foreach(arg, ((Expr *)tree)->args)
{
lfirst(arg) = intersect_tree_analyze(lfirst(arg), first_select, parsetree);
}
result = tree;
}
return result;
}

89
src/backend/rewrite/rewriteManip.c
View File

@ -6,7 +6,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteManip.c,v 1.23 1998/12/14 00:02:17 thomas Exp $
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteManip.c,v 1.24 1999/01/18 00:09:56 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -152,7 +152,10 @@ OffsetVarNodes(Node *node, int offset, int sublevels_up)
case T_SubLink:
{
SubLink *sub = (SubLink *)node;
List *tmp_oper, *tmp_lefthand;
/* We also have to adapt the variables used in sub->lefthand
* and sub->oper */
OffsetVarNodes(
(Node *)(sub->lefthand),
offset,
@ -162,6 +165,19 @@ OffsetVarNodes(Node *node, int offset, int sublevels_up)
(Node *)(sub->subselect),
offset,
sublevels_up + 1);
/***S*I***/
/* Make sure the first argument of sub->oper points to the
* same var as sub->lefthand does otherwise we will
* run into troubles using aggregates (aggno will not be
* set correctly) */
tmp_lefthand = sub->lefthand;
foreach(tmp_oper, sub->oper)
{
lfirst(((Expr *) lfirst(tmp_oper))->args) =
lfirst(tmp_lefthand);
tmp_lefthand = lnext(tmp_lefthand);
}
}
break;
@ -364,7 +380,8 @@ ChangeVarNodes(Node *node, int rt_index, int new_index, int sublevels_up)
case T_SubLink:
{
SubLink *sub = (SubLink *)node;
List *tmp_oper, *tmp_lefthand;
ChangeVarNodes(
(Node *)(sub->lefthand),
rt_index,
@ -376,6 +393,19 @@ ChangeVarNodes(Node *node, int rt_index, int new_index, int sublevels_up)
rt_index,
new_index,
sublevels_up + 1);
/***S*I***/
/* Make sure the first argument of sub->oper points to the
* same var as sub->lefthand does otherwise we will
* run into troubles using aggregates (aggno will not be
* set correctly) */
tmp_lefthand = sub->lefthand;
foreach(tmp_oper, sub->oper)
{
lfirst(((Expr *) lfirst(tmp_oper))->args) =
lfirst(tmp_lefthand);
tmp_lefthand = lnext(tmp_lefthand);
}
}
break;
@ -465,7 +495,10 @@ AddQual(Query *parsetree, Node *qual)
if (qual == NULL)
return;
copy = copyObject(qual);
/***S*I***/
/* copy = copyObject(qual); */
copy = qual;
old = parsetree->qual;
if (old == NULL)
parsetree->qual = copy;
@ -485,7 +518,10 @@ AddHavingQual(Query *parsetree, Node *havingQual)
if (havingQual == NULL)
return;
copy = copyObject(havingQual);
/***S*I***/
copy = havingQual;
/* copy = copyObject(havingQual); */
old = parsetree->havingQual;
if (old == NULL)
parsetree->havingQual = copy;
@ -494,6 +530,20 @@ AddHavingQual(Query *parsetree, Node *havingQual)
(Node *) make_andclause(makeList(parsetree->havingQual, copy, -1));
}
void
AddNotHavingQual(Query *parsetree, Node *havingQual)
{
Node *copy;
if (havingQual == NULL)
return;
/***S*I***/
/* copy = (Node *)make_notclause( (Expr *)copyObject(havingQual)); */
copy = (Node *) make_notclause((Expr *)havingQual);
AddHavingQual(parsetree, copy);
}
void
AddNotQual(Query *parsetree, Node *qual)
@ -503,7 +553,9 @@ AddNotQual(Query *parsetree, Node *qual)
if (qual == NULL)
return;
copy = (Node *) make_notclause(copyObject(qual));
/***S*I***/
/* copy = (Node *) make_notclause((Expr *)copyObject(qual)); */
copy = (Node *) make_notclause((Expr *)qual);
AddQual(parsetree, copy);
}
@ -835,7 +887,7 @@ HandleRIRAttributeRule(Query *parsetree,
rt_index, attr_num, modified, badsql, 0);
}
#ifdef NOT_USED
static void
nodeHandleViewRule(Node **nodePtr,
List *rtable,
@ -976,10 +1028,19 @@ nodeHandleViewRule(Node **nodePtr,
{
SubLink *sublink = (SubLink *) node;
Query *query = (Query *) sublink->subselect;
List *tmp_lefthand, *tmp_oper;
nodeHandleViewRule((Node **) &(query->qual), rtable, targetlist,
rt_index, modified, sublevels_up + 1);
/***S*H*D***/
nodeHandleViewRule((Node **) &(query->havingQual), rtable, targetlist,
rt_index, modified, sublevels_up + 1);
nodeHandleViewRule((Node **) &(query->targetList), rtable, targetlist,
rt_index, modified, sublevels_up + 1);
/*
* We also have to adapt the variables used in
* sublink->lefthand and sublink->oper
@ -993,10 +1054,17 @@ nodeHandleViewRule(Node **nodePtr,
* will run into troubles using aggregates (aggno will not
* be set correctly
*/
pfree(lfirst(((Expr *) lfirst(sublink->oper))->args));
lfirst(((Expr *) lfirst(sublink->oper))->args) =
lfirst(sublink->lefthand);
}
/* pfree(lfirst(((Expr *) lfirst(sublink->oper))->args)); */
/***S*I***/
tmp_lefthand = sublink->lefthand;
foreach(tmp_oper, sublink->oper)
{
lfirst(((Expr *) lfirst(tmp_oper))->args) =
lfirst(tmp_lefthand);
tmp_lefthand = lnext(tmp_lefthand);
}
}
break;
default:
/* ignore the others */
@ -1004,7 +1072,6 @@ nodeHandleViewRule(Node **nodePtr,
}
}
#ifdef NOT_USED
void
HandleViewRule(Query *parsetree,
List *rtable,

18
src/backend/tcop/postgres.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.96 1999/01/17 06:18:42 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.97 1999/01/18 00:09:56 momjian Exp $
*
* NOTES
* this is the "main" module of the postgres backend and
@ -448,12 +448,20 @@ pg_parse_and_plan(char *query_string, /* string to execute */
querytree = querytree_list->qtrees[i];
/***S*I***/
/* Rewrite Union, Intersect and Except Queries
* to normal Union Queries using IN and NOT IN subselects */
if(querytree->intersectClause != NIL)
{
querytree = Except_Intersect_Rewrite(querytree);
}
if (DebugPrintQuery)
{
if (DebugPrintQuery > 3)
{
/* Print the query string as is if query debug level > 3 */
TPRINTF(TRACE_QUERY, "query: %s", query_string);
{
/* Print the query string as is if query debug level > 3 */
TPRINTF(TRACE_QUERY, "query: %s", query_string);
}
else
{
@ -1527,7 +1535,7 @@ PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[])
if (!IsUnderPostmaster)
{
puts("\nPOSTGRES backend interactive interface ");
puts("$Revision: 1.96 $ $Date: 1999/01/17 06:18:42 $\n");
puts("$Revision: 1.97 $ $Date: 1999/01/18 00:09:56 $\n");
}
/* ----------------

5
src/include/executor/nodeGroup.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: nodeGroup.h,v 1.7 1998/09/01 04:35:56 momjian Exp $
* $Id: nodeGroup.h,v 1.8 1999/01/18 00:10:02 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -22,5 +22,8 @@ extern bool ExecInitGroup(Group *node, EState *estate, Plan *parent);
extern int ExecCountSlotsGroup(Group *node);
extern void ExecEndGroup(Group *node);
extern void ExecReScanGroup(Group *node, ExprContext *exprCtxt, Plan *parent);
/***S*I***/
extern void ExecReScanGroup(Group *node, ExprContext *exprCtxt, Plan *parent);
#endif /* NODEGROUP_H */

13
src/include/nodes/parsenodes.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: parsenodes.h,v 1.65 1999/01/05 15:45:49 vadim Exp $
* $Id: parsenodes.h,v 1.66 1999/01/18 00:10:06 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -58,6 +58,9 @@ typedef struct Query
* BY */
Node *havingQual; /* qualification of each group */
/***S*I***/
List *intersectClause;
List *unionClause; /* unions are linked under the previous
* query */
Node *limitOffset; /* # of result tuples to skip */
@ -605,7 +608,9 @@ typedef struct InsertStmt
List *groupClause; /* group by clause */
Node *havingClause; /* having conditional-expression */
List *unionClause; /* union subselect parameters */
bool unionall; /* union without unique sort */
bool unionall; /* union without unique sort */
/***S*I***/
List *intersectClause;
} InsertStmt;
/* ----------------------
@ -646,6 +651,10 @@ typedef struct SelectStmt
Node *whereClause; /* qualifications */
List *groupClause; /* group by clause */
Node *havingClause; /* having conditional-expression */
/***S*I***/
List *intersectClause;
List *exceptClause;
List *unionClause; /* union subselect parameters */
List *sortClause; /* sort clause (a list of SortGroupBy's) */
char *portalname; /* the portal (cursor) to create */

5
src/include/parser/analyze.h
View File

@ -5,7 +5,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: analyze.h,v 1.4 1998/09/01 04:37:25 momjian Exp $
* $Id: analyze.h,v 1.5 1999/01/18 00:10:11 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -15,5 +15,8 @@
#include <parser/parse_node.h>
extern QueryTreeList *parse_analyze(List *pl, ParseState *parentParseState);
/***S*I***/
extern void create_select_list(Node *ptr, List **select_list, bool *unionall_present);
extern Node *A_Expr_to_Expr(Node *ptr, bool *intersect_present);
#endif /* ANALYZE_H */

8
src/include/rewrite/rewriteHandler.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: rewriteHandler.h,v 1.6 1998/09/01 04:38:01 momjian Exp $
* $Id: rewriteHandler.h,v 1.7 1999/01/18 00:10:12 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -34,5 +34,9 @@ typedef struct _rewrite_meta_knowledge RewriteInfo;
extern List *QueryRewrite(Query *parsetree);
/***S*I***/
extern Query *Except_Intersect_Rewrite(Query *parsetree);
extern void create_list(Node *ptr, List **intersect_list);
extern Node *intersect_tree_analyze(Node *tree, Node *first_select, Node *parsetree);
extern void check_targetlists_are_compatible(List *prev_target, List *current_target);
#endif /* REWRITEHANDLER_H */

4
src/include/rewrite/rewriteManip.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: rewriteManip.h,v 1.11 1998/10/21 16:21:29 momjian Exp $
* $Id: rewriteManip.h,v 1.12 1999/01/18 00:10:16 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -25,6 +25,8 @@ void AddQual(Query *parsetree, Node *qual);
void AddHavingQual(Query *parsetree, Node *havingQual);
void AddNotQual(Query *parsetree, Node *qual);
void AddNotHavingQual(Query *parsetree, Node *havingQual);
void FixNew(RewriteInfo *info, Query *parsetree);
void HandleRIRAttributeRule(Query *parsetree, List *rtable, List *targetlist,

9
src/include/utils/elog.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: elog.h,v 1.8 1998/09/01 04:39:03 momjian Exp $
* $Id: elog.h,v 1.9 1999/01/18 00:10:17 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -29,7 +29,12 @@
#define ABORTX 0x4000 /* abort process after logging */
#endif
#define ELOG_MAXLEN 4096
/***S*I***/
/* Increase this to be able to use postmaster -d 3 with complex
* view definitions (which are transformed to very, very large INSERT statements
* and if -d 3 is used the query string of these statements is printed using
* vsprintf which expects enough memory reserved! */
#define ELOG_MAXLEN 12288
/* uncomment the following if you want your elog's to be timestamped */