involving HashAggregate over SubqueryScan (this is the known case, there
may well be more). The bug is only latent in releases before 8.2 since they
didn't try to access tupletable slots' descriptors during ExecDropTupleTable.
The least bogus fix seems to be to make subqueries share the parent query's
memory context, so that tupdescs they create will have the same lifespan as
those of the parent query. There are comments in the code envisioning going
even further by not having a separate child EState at all, but that will
require rethinking executor access to range tables, which I don't want to
tackle right now. Per bug report from Jean-Pierre Pelletier.
ps_TupFromTlist in plan nodes that make use of it. This was being done
correctly in join nodes and Result nodes but not in any relation-scan nodes.
Bug would lead to bogus results if a set-returning function appeared in the
targetlist of a subquery that could be rescanned after partial execution,
for example a subquery within EXISTS(). Bug has been around forever :-(
... surprising it wasn't reported before.
were marked canSetTag. While it's certainly correct to return the result
of the last one that is marked canSetTag, it's less clear what to do when
none of them are. Since plpgsql will complain if zero is returned, the
8.2.0 behavior isn't good. I've fixed it to restore the prior behavior of
returning the physically last query's result code when there are no
canSetTag queries.
pgbench calls random() later, so it should have called srandom().
On most platforms except Windows srandom() is actually identical
to srand(), so the bug only bites Windows users.
per bug report from Akio Ishida.
Use a TRY block instead of (inadequate) ad-hoc coding to ensure that
libxml is cleaned up after a failure. Report the intended SQLCODE
instead of defaulting to XX000. Avoid risking use of a dangling
pointer by keeping the persistent error buffer in TopMemoryContext.
Be less trusting that error messages don't contain %.
This patch doesn't do anything about changing the way the messages
are put together --- this is just about mechanism.
bletcherous and unsafe manipulation of global encoding setting.
Clean up libxml reporting mechanism a bit (it still looks like a
dangling-pointer crash waiting to happen, though, not to mention
being far less than sane from a localization standpoint).
the XmlExpr code in various lists, use a representation that has some hope
of reverse-listing correctly (though it's still a de-escaping function
shy of correctness), generally try to make it look more like Postgres
coding conventions.
cases. Operator classes now exist within "operator families". While most
families are equivalent to a single class, related classes can be grouped
into one family to represent the fact that they are semantically compatible.
Cross-type operators are now naturally adjunct parts of a family, without
having to wedge them into a particular opclass as we had done originally.
This commit restructures the catalogs and cleans up enough of the fallout so
that everything still works at least as well as before, but most of the work
needed to actually improve the planner's behavior will come later. Also,
there are not yet CREATE/DROP/ALTER OPERATOR FAMILY commands; the only way
to create a new family right now is to allow CREATE OPERATOR CLASS to make
one by default. I owe some more documentation work, too. But that can all
be done in smaller pieces once this infrastructure is in place.
operator strategy numbers, ie, GiST and GIN. This is almost cosmetic
enough to not need a catversion bump, but since the opr_sanity regression
test has to change in sync with the catalog entry, I figured I'd better
do one.
are all in new-in-8.2 logic associated with indexability of ScalarArrayOpExpr
(IN-clauses) or amortization of indexscan costs across repeated indexscans
on the inside of a nestloop. In particular:
Fix some logic errors in the estimation for multiple scans induced by a
ScalarArrayOpExpr indexqual.
Include a small cost component in bitmap index scans to reflect the costs of
manipulating the bitmap itself; this is mainly to prevent a bitmap scan from
appearing to have the same cost as a plain indexscan for fetching a single
tuple.
Also add a per-index-scan-startup CPU cost component; while prior releases
were clearly too pessimistic about the cost of repeated indexscans, the
original 8.2 coding allowed the cost of an indexscan to effectively go to zero
if repeated often enough, which is overly optimistic.
Pay some attention to index correlation when estimating costs for a nestloop
inner indexscan: this is significant when the plan fetches multiple heap
tuples per iteration, since high correlation means those tuples are probably
on the same or adjacent heap pages.
properly.
Remove SGML docs about openjade performance patch, and instead add
comment in style sheet where indenting code is commented out.
Backpatch to 8.2.X.
>
> * Embedded server (not wanted)
>
> While PostgreSQL clients runs fine limited-resource environments, the
> server requires multiple processes and a stable pool of resources to
> run reliabily and efficiently. Stripping down the PostgreSQL server
> to run in the same process address space as the client application
> would add too much complexity and failure cases.
< * Have EXPLAIN ANALYZE highlight poor optimizer estimates
> * Have EXPLAIN ANALYZE issue NOTICE messages when the estimated and
> actual row counts differ by a specified percentage
joinclause doesn't use any outer-side vars) requires a "bushy" plan to be
created. The normal heuristic to avoid joins with no joinclause has to be
overridden in that case. Problem is new in 8.2; before that we forced the
outer join order anyway. Per example from Teodor.
Tom Lane
Teodor Sigaev
Tatsuo Ishii
Bruce Momjian
Peter Eisentraut
Andrew Dunstan