Tom Lane [Mon, 21 Jun 1999 01:26:56 +0000 (01:26 +0000)]
Replace rewriter's checkQueryHasAggs and checkQueryHasSubLink
with expression_tree_walker-based code. The former failed to cope with
expressions containing SubLinks, and the latter returned TRUE for both
SubLinks and Aggrefs (cut-and-paste bug?). There is a lot more scope for
using expression_tree_walker in this module, but I'll restrain myself
until the 6.6 split occurs from touching not-demonstrably-broken code.
Tom Lane [Mon, 21 Jun 1999 01:20:57 +0000 (01:20 +0000)]
Clean up problems with sublinks + grouping in planner. Not
sure if they are all fixed, because rewriter is now the stumbling block,
but at least some cases work that did not work before.
Tom Lane [Sat, 19 Jun 1999 03:48:31 +0000 (03:48 +0000)]
My first chosen victim for expression_tree_walker conversion
is parse_aggs.c. This fixes its failure to cope with (at least) CaseExpr
and ArrayRef nodes, which is the reason why both of these fail in 6.5:
select coalesce(f1,0) from int4_tbl group by f1;
ERROR: Illegal use of aggregates or non-group column in target list
select sentence.words[0] from sentence group by sentence.words[0];
ERROR: Illegal use of aggregates or non-group column in target list
The array case still fails, but at least it's not parse_agg's fault
anymore ... considering that we now support CASE officially, I think
it's important to fix the first example ...
Tom Lane [Sat, 19 Jun 1999 03:41:45 +0000 (03:41 +0000)]
Create a generic expression-tree-walker subroutine, which
will gradually replace all of the boilerplate tree-walk-recursion code that
currently exists in O(N) slightly different forms in N subroutines.
I've had it with adding missing cases to these subroutines...
Tom Lane [Sat, 19 Jun 1999 00:44:44 +0000 (00:44 +0000)]
Temporarily disable error checks for missing selectivity
functions, in order to work around oversight in 6.5 release: rtree
index functions haven't got any. Mea culpa ...
Incorporate fixes from Date and Darwen, 1997.
Did not check the function declarations as carefully as the other parts,
though all of the function names *do* match up with D&D.
Tom Lane [Thu, 17 Jun 1999 22:21:41 +0000 (22:21 +0000)]
Defend against function calls with more than 8 arguments (code
used to overrun its fixed-size arrays before detecting error; not cool).
Also, replace uses of magic constant '8' with 'MAXFARGS'.
Add CLI required header and examples from SQL3/SQL98
August 1994 draft standard.
Use the ecpg support libraries to write the CLI interface?
Date and Darwen claim that CLI is a more modern and flexible approach...
Release notes from sgml.
Came out with max 79 columns from Applix by defining the page width at
10 inches and the right margin at 9.5 inches, then exporting
as "ASCII Layout".
Tom Lane [Sat, 12 Jun 1999 22:17:24 +0000 (22:17 +0000)]
Move default NBuffers setting into config.h, and rename it
to DEF_NBUFFERS for readability. Make sure the default value is OK
according to postmaster.c's new sanity check for -B values.
Tom Lane [Sat, 12 Jun 1999 20:41:25 +0000 (20:41 +0000)]
Fix critical error noticed by Massimo: copy.c used to have a
special hack to ensure it would close its output file even after failure
due to elog(ERROR) partway through the copy. This is now unnecessary
because fd.c takes care of cleaning up open files at transaction abort;
worse, after fd.c closed the file copy.c would try to do so *again* at
the start of the next COPY command. This would result in havoc in most
implementations of stdio library.
Tom Lane [Sat, 12 Jun 1999 19:38:30 +0000 (19:38 +0000)]
Remove query_planner's overhasty rejection of cases where
tlist and qual are NULL. It ought to handle these the same as the cases
where tlist contains only constant expressions, ie, be willing to generate
a Result-node plan. This did not use to matter, but it does now because
union_planner will flatten the tlist when aggregates are present. Thus,
'select count(1) from table' now causes query_planner to be given a null
tlist, and to duplicate 6.4's behavior we need it to give back a Result
plan rather than refusing the query. 6.4 was arguably doing the Wrong
Thing for this query, but I'm not going to open a semantics issue right
before 6.5 release ... can revisit that problem later.
Tom Lane [Sat, 12 Jun 1999 19:27:41 +0000 (19:27 +0000)]
Plug hole in dike: planner would coredump if query_planner
returned NULL, which it will do in some cases where an elog(ERROR) would
probably be more appropriate. For the moment, generate a not-very-
informative error message rather than proceeding to certain coredump.
Probably ought to think about making query_planner elog instead of
returning NULL, but this is at least a safe change for now.
Tom Lane [Sat, 12 Jun 1999 19:22:40 +0000 (19:22 +0000)]
When targetlist is NULL, ExecTargetList was passing back a
pointer to palloc'd but uninitialized memory. This is not cool; anyone looking
at the returned 'tuple' would at best coredump and at worst behave in a
bizarre and irreproducible way. Fix it to return a predictable value,
namely a correctly-set-up palloc'd tuple containing zero attributes.
I believe this fix is both safe and critical.
Bruce Momjian [Sat, 12 Jun 1999 14:05:41 +0000 (14:05 +0000)]
I don't like last minute patches before the final freeze, but I believe that
this one could be useful for people experiencing out-of-memory crashes while
executing queries which retrieve or use a very large number of tuples.
The problem happens when storage is allocated for functions results used in
a large query, for example:
select upper(name) from big_table;
select big_table.array[1] from big_table;
select count(upper(name)) from big_table;
This patch is a dirty hack that fixes the out-of-memory problem for the most
common cases, like the above ones. It is not the final solution for the
problem but it can work for some people, so I'm posting it.
The patch should be safe because all changes are under #ifdef. Furthermore
the feature can be enabled or disabled at runtime by the `free_tuple_memory'
options in the pg_options file. The option is disabled by default and must
be explicitly enabled at runtime to have any effect.
To enable the patch add the follwing line to Makefile.custom:
CUSTOM_COPT += -DFREE_TUPLE_MEMORY
To enable the option at runtime add the following line to pg_option:
Vadim B. Mikheev [Fri, 11 Jun 1999 09:35:08 +0000 (09:35 +0000)]
Change Assert(Ptp.t_data->t_xmax == tp.t_data->t_xmin) to :
/*
* Read above about cases when !ItemIdIsUsed(Citemid)
* (child item is removed)... Due to the fact that
* at the moment we don't remove unuseful part of
* update-chain, it's possible to get too old
* parent row here. Like as in the case which
* caused this problem, we stop shrinking here.
* I could try to find real parent row but want
* not to do it because of real solution will
* be implemented anyway, latter, and we are too
* close to 6.5 release. - vadim 06/11/99
*/
if (Ptp.t_data->t_xmax != tp.t_data->t_xmin)
...
Vadim B. Mikheev [Thu, 10 Jun 1999 14:17:12 +0000 (14:17 +0000)]
1. Fix for elog(ERROR, "EvalPlanQual: t_xmin is uncommitted ?!")
and possibly for other cases too:
DO NOT cache status of transaction in unknown state
(i.e. non-committed and non-aborted ones)
Example:
T1 reads row updated/inserted by running T2 and cache T2 status.
T2 commits.
Now T1 reads a row updated by T2 and with HEAP_XMAX_COMMITTED
in t_infomask (so cached T2 status is not changed).
Now T1 EvalPlanQual gets updated row version without HEAP_XMIN_COMMITTED
-> TransactionIdDidCommit(t_xmin) and TransactionIdDidAbort(t_xmin)
return FALSE and T2 decides that t_xmin is not committed and gets
ERROR above.
It's too late to find more smart way to handle such cases and so
I just changed xact status caching and got rid TransactionIdFlushCache()
from code.
Changed: transam.c, xact.c, lmgr.c and transam.h - last three
just because of TransactionIdFlushCache() is removed.
2. heapam.c:
T1 marked a row for update. T2 waits for T1 commit/abort.
T1 commits. T3 updates the row before T2 locks row page.
Now T2 sees that new row t_xmax is different from xact id (T1)
T2 was waiting for. Old code did Assert here. New one goes to
HeapTupleSatisfiesUpdate. Obvious changes too.
3. Added Assert to vacuum.c
4. bufmgr.c: break
Assert(buf->r_locks == 0 && !buf->ri_lock)
into two Asserts.
Tom Lane [Thu, 10 Jun 1999 06:55:40 +0000 (06:55 +0000)]
Fix errors in SELECT ... GROUP BY ... UNION SELECT ...
ye proverbial one-line patch (not counting five lines of comment so's
maybe it won't happen again)
Reset evaluation plan tuple table next free slot counter to 0
after ExecEndNode. It must be done! Or we'll be out of free
tuple slots very soon, though slots are freed by ExecEndNode
and ready for reusing.
code in InitPlan - i.e. extra 10 slots. Simple select uses
3 slots and so it was possible to re-use evaluation plan
3 additional times and didn't get
elog(NOTICE, "Plan requires more slots than are available");
elog(ERROR, "send mail to your local executor guru to fix this");
Changes are obvious and shouldn't be problems with them.
Though, I added Assert(epqstate->es_tupleTable->next == 0)
before EvalPlanQual():ExecInitNode and we'll notice if
something is still wrong. Is it better to change Assert
to elog(ERROR) ?