about typmod representation for standard types out into type-specific
typmod I/O functions.  Teodor Sigaev, with some editorialization by
Tom Lane.

or contradictory keys even in cross-data-type scenarios.  This is another
benefit of the opfamily rewrite: we can find the needed comparison
operators now.

predicate operators.  The hard stuff turns out to be already done in the
previous commit, we need merely open the floodgates...

of increasing size, instead of one at a time.  This reduces the memory
management overhead when num_temp_buffers is large: in the previous coding
we would actually waste 50% of the space used for temp buffers, because aset.c
would round the individual requests up to 16K.  Problem noted while studying
a performance issue reported by Steven Flatt.

Back-patch as far as 8.1 --- older versions used few enough local buffers
that the issue isn't significant for them.

has a small maxBlockSize: the maximum request size that we will treat as a
"chunk" needs to be limited to fit in maxBlockSize.  Otherwise we will round
up the request size to the next power of 2, wasting space, which is a bit
pointless if we aren't going to make the blocks big enough to fit additional
stuff in them.  The example motivating this is local buffer management, which
makes repeated allocations of 8K (one BLCKSZ buffer) in TopMemoryContext,
which has maxBlockSize = 8K because for the most part allocations there are
small.  This leads to each local buffer actually eating 16K of space, which
adds up when there are thousands of them.  I intend to change localbuf.c to
aggregate its requests, which will prevent this particular misbehavior, but
it seems likely that similar scenarios could arise elsewhere, so fixing the
core problem seems wise as well.

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.

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.

require at least two characters for uniqueness.   This now matches the
behavior of other boolean strings we support, per report from Gurjeet
Singh.

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.

necessary.

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.

representing externally-supplied values, since the APIs that carry such
values only specify type not typmod.  However, for PARAM_SUBLINK Params
it is handy to carry the typmod of the sublink's output column.  This
is a much cleaner solution for the recently reported 'could not find
pathkey item to sort' and 'failed to find unique expression in subplan
tlist' bugs than my original 8.2-compatible patch.  Besides, someday we
might want to support typmods for external parameters ...

in normal operation, and we can avoid rewriting pg_control at every log
segment switch if we don't insist that these values be valid.  Reducing
the number of pg_control updates is a good idea for both performance and
reliability.  It does make pg_resetxlog's life a bit harder, but that seems
a good tradeoff; and anyway the change to pg_resetxlog amounts to automating
something people formerly needed to do by hand, namely look at the existing
pg_xlog files to make sure the new WAL start point was past them.

In passing, change the wording of xlog.c's "database system was interrupted"
messages: describe the pg_control timestamp as "last known up at" rather than
implying it is the exact time of service interruption.  With this change the
timestamp will generally be the time of the last checkpoint, which could be
many minutes before the failure; and we've already seen indications that
people tend to misinterpret the old wording.

initdb forced due to change in pg_control layout.  Simon Riggs and Tom Lane

the nonexistent ShowStats variable is simply removed, per Gavin Sherry.

release it in a subtransaction abort, but this neglects possibility that
someone outside SPI already did.  Fix is for spi.c to forget about a tuptable
as soon as it's handed it back to the caller.
Per bug #2817 from Michael Andreen.

rearrangeable outer joins and the WHERE clause is non-strict and mentions
only nullable-side relations.  New bug in 8.2, caused by new logic to allow
rearranging outer joins.  Per bug #2807 from Ross Cohen; thanks to Jeff
Davis for producing a usable test case.

a sublink's test expression have the correct vartypmod, rather than defaulting
to -1.  There's at least one place where this is important because we're
expecting these Vars to be exactly equal() to those appearing in the subplan
itself.  This is a pretty klugy solution --- it would likely be cleaner to
change Param nodes to include a typmod field --- but we can't do that in the
already-released 8.2 branch.
Per bug report from Hubert Fongarnand.

identify long-running transactions. Since we already need to record
the transaction-start time (e.g. for now()), we don't need any
additional system calls to report this information.

Catversion bumped, initdb required.

capitalize the strings like sentences. Remove unnecessarily
specific descriptions of the units used by GUC variables, since
we now allow any reasonable unit to be specified.

FormatMessage() (This should have been in 8.2.0, patched to 8.2.X and
HEAD):

I think this problem to be complex....
http://archives.postgresql.org/pgsql-hackers/2006-11/msg00042.php

FormatMessage of windows cannot consider the encoding of the database.
However, I should try the solution now. It is necessary to clear the
problem.

Multi character-code exists together in message and log. It doesn't
consider
the data base encoding that the user intended....

The user in multi-byte country can try this.
http://inet.winpg.jp/~saito/pg_bug/MessageCheck.c

That is, it is likely to become it in this manner.(Japanese)
http://inet.winpg.jp/~saito/pg_bug/FormatMessage998.png

Hiroshi Saito

by name on each and every row processed.  Profiling suggests this may
buy a percent or two for simple UPDATE scenarios, which isn't huge,
but when it's so easy to get ...

by the change to make limit values int8 instead of int4.  (Specifically, you
can do DatumGetInt32 safely on a null value, but not DatumGetInt64.)  Per
bug #2803 from Greg Johnson.

should allow delete-pending files to actually go away, and thereby work
around the various complaints we've seen about 'permission denied'
errors in such cases.  Should be reasonably harmless in any case...

StartupXLOG and ShutdownXLOG no longer need to be critical sections, because
in all contexts where they are invoked, elog(ERROR) would be translated to
elog(FATAL) anyway.  (One change in bgwriter.c is needed to make this true:
set ExitOnAnyError before trying to exit.  This is a good fix anyway since
the existing code would have gone into an infinite loop on elog(ERROR) during
shutdown.)  That avoids a misleading report of PANIC during semi-orderly
failures.  Modify the postmaster to include the startup process in the set of
processes that get SIGTERM when a fast shutdown is requested, and also fix it
to not try to restart the bgwriter if the bgwriter fails while trying to write
the shutdown checkpoint.  Net result is that "pg_ctl stop -m fast" does
something reasonable for a system in warm standby mode, and so should Unix
system shutdown (ie, universal SIGTERM).  Per gripe from Stephen Harris and
some corner-case testing of my own.

remove page on next level linked from next inner page, ginScanToDelete()
wrongly sets parent page. Bug reveals when many item pointers from index
was deleted ( several hundred thousands).

Bug is discovered by hubert depesz lubaczewski <depesz@gmail.com>

Suppose, we need rc2 before release...