While this doesn't save a huge amount of runtime, it still seems worth
doing, especially since I realized that the data copying I did in my first
draft was quite unnecessary.  In this version, once we have the results
cached, getting them back for re-use is really very cheap.

Also, remove the hard-wired limitation to not consider wctype.h results for
character codes above 255.  It turns out that we can't push the limit as
far up as I'd originally hoped, because the regex colormap code is not
efficient enough to cope very well with character classes containing many
thousand letters, which a Unicode locale is entirely capable of producing.
Still, we can push it up to U+7FF (which I chose as the limit of 2-byte
UTF8 characters), which will at least make Eastern Europeans happy pending
a better solution.  Thus, this commit resolves the specific complaint in
bug #6457, but not the more general issue that letters of non-western
alphabets are mostly not recognized as matching [[:alpha:]].

Create src/backend/regex/README to hold an implementation overview of
the regex package, and fill it in with some preliminary notes about
the code's DFA/NFA processing and colormap management.  Much more to
do there of course.

Also, improve some code comments around the colormap and cvec code.
No functional changes except to add one missing assert.

Some line feeds are added to target lists and from lists to make
them more readable. By default they wrap at 80 columns if possible,
but the wrap column is also selectable - if 0 it wraps after every
item.

Andrew Dunstan, reviewed by Hitoshi Harada.

anymore. This way we don't have to worry which compiler on which OS offers
which version of strtok.

This file was missed in commit 4c6cedd1.

Sync our regex code with upstream changes since last time we did this,
which was Tcl 8.5.0 (see commit df1e965e).

There are no functional changes here; the main point is just to lay down
a commit-log marker that somebody has looked at this recently, and to do
what we can to keep the two codebases comparable.

The array intersection code would give wrong results if the first entry of
the correct output array would be "1".  (I think only this value could be
at risk, since the previous word would always be a lower-bound entry with
that fixed value.)

Problem spotted by Julien Rouhaud, initial patch by Guillaume Lelarge,
cosmetic improvements by me.

Formerly, we just punted when trying to estimate stats for variables coming
out of sub-queries using DISTINCT, on the grounds that whatever stats we
might have for underlying table columns would be inapplicable.  But if the
sub-query has only one DISTINCT column, we can consider its output variable
as being unique, which is useful information all by itself.  The scope of
this improvement is pretty narrow, but it costs nearly nothing, so we might
as well do it.  Per discussion with Andres Freund.

This patch differs from the draft I submitted yesterday in updating various
comments about vardata.isunique (to reflect its extended meaning) and in
tweaking the interaction with security_barrier views.  There does not seem
to be a reason why we can't use this sort of knowledge even when the
sub-query is such a view.

Use exit_horribly() and ExecuteSqlQueryForSingleRow() in various
places where it's equivalent, or nearly equivalent, to the prior
coding. Apart from being more compact, this also makes the error
messages for the wrong-number-of-tuples case more consistent.

Parallel pg_dump wants to have multiple ArchiveHandle objects, and
therefore multiple PGconns, in play at the same time.  This should
be just about the end of the refactoring that we need in order to
make that workable.

Any patches apt to get broken have probably already been broken by the
error-handling cleanups I just did, so we might as well clean this up
at the same time.

Per recent discussions on pgsql-hackers regarding parallel pg_dump.

This extends the changes of commit 6252c4f9
so that we run the cleanup hook earlier for failure cases as well as
success cases.  As before, the point is to avoid an assertion failure from
an Assert I added in commit a874fe7b, which
was meant to check that no user-written code can be called during portal
cleanup.  This fixes a case reported by Pavan Deolasee in which the Assert
could be triggered during backend exit (see the new regression test case),
and also prevents the possibility that the cleanup hook is run after
portions of the portal's state have already been recycled.  That doesn't
really matter in current usage, but it foreseeably could matter in the
future.

Back-patch to 9.1 where the Assert in question was added.

The relevant commit is 337b6f5e.

Idea from Peter.

This is some preliminary refactoring related to a pending patch
to allow sepgsql-enable sessions to make dynamic label transitions.
But this commit doesn't involve any functional change: it just puts
some bits of code in more logical places.

KaiGai Kohei

Per recent work by Peter Geoghegan, it's significantly faster to
tuplesort on a single sortkey if ApplySortComparator is inlined into
quicksort rather reached via a function pointer.  It's also faster
in general to have a version of quicksort which is specialized for
sorting SortTuple objects rather than objects of arbitrary size and
type.  This requires a couple of additional copies of the quicksort
logic, which in this patch are generate using a Perl script.  There
might be some benefit in adding further specializations here too,
but thus far it's not clear that those gains are worth their weight
in code footprint.

Along the way, move create_function_3 into a parallel schedule.

KaiGai Kohei

Because it isn't good to be able to turn things on, and not off again.

Per report from Christoph Berg.

comments about the alarm method used on Win32.

thread.

caching.

The hstore and json datatypes both have record-conversion functions that
pay attention to column names in the composite values they're handed.
We used to not worry about inserting correct field names into tuple
descriptors generated at runtime, but given these examples it seems
useful to do so.  Observe the nicer-looking results in the regression
tests whose results changed.

catversion bump because there is a subtle change in requirements for stored
rule parsetrees: RowExprs from ROW() constructs now have to include field
names.

Andrew Dunstan and Tom Lane

in about 30 seconds.

test, rather than a number of test cycles.  Changes -o/cycles option to
-s/seconds.

Per buildfarm.

Per buildfarm.

We don't normally allow quals to be pushed down into a view created
with the security_barrier option, but functions without side effects
are an exception: they're OK.  This allows much better performance in
common cases, such as when using an equality operator (that might
even be indexable).

There is an outstanding issue here with the CREATE FUNCTION / ALTER
FUNCTION syntax: there's no way to use ALTER FUNCTION to unset the
leakproof flag.  But I'm committing this as-is so that it doesn't
have to be rebased again; we can fix up the grammar in a future
commit.

KaiGai Kohei, with some wordsmithing by me.

With a unique counter being added anyway, there is no need anymore to have the variable name listed, too.

Problem reported by Peter Eisentraut.

Backpatched to release 9.0.

If tuples were toasted, heap_multi_insert didn't update the ctid on the
original tuples. This caused a failure if there was an after trigger
(including a foreign key), on the table, and a tuple got toasted.

Per off-list report and test case from Ted Phelps

Alex Hunsaker

Datatype I/O functions are allowed to leak memory in CurrentMemoryContext,
since they are generally called in short-lived contexts.  However, plpgsql
calls such functions for purposes of type conversion, and was calling them
in its procedure context.  Therefore, any leaked memory would not be
recovered until the end of the plpgsql function.  If such a conversion
was done within a loop, quite a bit of memory could get consumed.  Fix by
calling such functions in the transient "eval_econtext", and adjust other
logic to match.  Back-patch to all supported versions.

Andres Freund, Jan Urbański, Tom Lane

If an extension has not been selected to be dumped (perhaps because of
a --schema or --table switch), the contents of its configuration tables
surely should not get dumped either.  Per gripe from
Hubert Depesz Lubaczewski.