Except all eliminates what it shouldnt
Gerzson Szinyei (gerzson@elender.hu) reports a bug with a severity of 1
The lower the number the more severe it is.
Short Description
Except all eliminates what it shouldnt
Long Description
"except all" eliminates records which had 2 instances in the original table, and one instance in the table to be eliminated. One instance should have showed up in the result.
When I filter the original table with "where field=nnnn", (the id of the problem record), and do the "except all" for only the records in questtion, the result is one instance as it should be.
Sample Code
http://www.webit.hu/~gerzson/pgexceptbugtest.tgz
No file was uploaded with this report
pgsql-bugs@postgresql.org writes:
Except all eliminates what it shouldnt
Hmm, nasty. It looks like all nested cases of INTERSECT/EXCEPT are
broken.
Attached is a patch I've applied to CVS sources (7.2-to-be). I don't
have enough confidence in it to back-patch it into 7.1.* right now,
but if you want to apply it locally I think it will work for you.
regards, tom lane
*** src/backend/optimizer/prep/prepunion.c.orig Tue Jun 5 01:26:04 2001
--- src/backend/optimizer/prep/prepunion.c Tue Aug 14 12:55:33 2001
***************
*** 275,286 ****
*
* The tlist for an Append plan isn't important as far as the Append is
* concerned, but we must make it look real anyway for the benefit of
! * the next plan level up.
*/
plan = (Plan *)
make_append(makeList2(lplan, rplan),
false,
! generate_setop_tlist(op->colTypes, 0, false,
lplan->targetlist,
refnames_tlist));--- 275,288 ----
*
* The tlist for an Append plan isn't important as far as the Append is
* concerned, but we must make it look real anyway for the benefit of
! * the next plan level up. In fact, it has to be real enough that the
! * flag column is shown as a variable not a constant, else setrefs.c
! * will get confused.
*/
plan = (Plan *)
make_append(makeList2(lplan, rplan),
false,
! generate_setop_tlist(op->colTypes, 2, false,
lplan->targetlist,
refnames_tlist));***************
*** 353,358 ****
--- 355,367 ---- /*
* Generate targetlist for a set-operation plan node
+ *
+ * colTypes: column datatypes for non-junk columns
+ * flag: -1 if no flag column needed, 0 or 1 to create a const flag column,
+ * 2 to create a variable flag column
+ * hack_constants: true to copy up constants (see comments in code)
+ * input_tlist: targetlist of this node's input node
+ * refnames_tlist: targetlist to take column names from
*/
static List *
generate_setop_tlist(List *colTypes, int flag,
***************
*** 414,432 **** if (flag >= 0)
{
! /* Add a resjunk column yielding specified flag value */
resdom = makeResdom((AttrNumber) resno++,
INT4OID,
-1,
pstrdup("flag"),
true);
! expr = (Node *) makeConst(INT4OID,
! sizeof(int4),
! Int32GetDatum(flag),
! false,
! true,
! false,
! false);
tlist = lappend(tlist, makeTargetEntry(resdom, expr));
}
--- 423,454 ---- if (flag >= 0)
{
! /* Add a resjunk flag column */
resdom = makeResdom((AttrNumber) resno++,
INT4OID,
-1,
pstrdup("flag"),
true);
! if (flag <= 1)
! {
! /* flag value is the given constant */
! expr = (Node *) makeConst(INT4OID,
! sizeof(int4),
! Int32GetDatum(flag),
! false,
! true,
! false,
! false);
! }
! else
! {
! /* flag value is being copied up from subplan */
! expr = (Node *) makeVar(0,
! resdom->resno,
! INT4OID,
! -1,
! 0);
! }
tlist = lappend(tlist, makeTargetEntry(resdom, expr));
}