For those variables only used when asserts are enabled, use a new
macro PG_USED_FOR_ASSERTS_ONLY, which expands to
__attribute__((unused)) when asserts are not enabled.

And minor other pgindent documentation tweaks.

Document that routine vacuuming is now also important for the purpose
of index-only scans; and mention in the section that describes the
visibility map that it is used to implement index-only scans.

Marti Raudsepp, with some changes by me.

This restores the pre-9.0 situation that it's possible to add new indexes
on pg_class and other mapped-but-not-shared catalogs, so long as you broke
the glass and flipped the big red Dont-Touch-Me switch.  As before, there
are a lot of gotchas, and you'd have to be pretty desperate to try this
on a production database; but there doesn't seem to be a reason for
relmapper.c to be preventing such things all by itself.  Per
experimentation with a case suggested by Cody Cutrer.

The prior coding instructs the user to pick an alternative maintenance
database, but this is overly clever, since it obscures whatever the real
cause of the failure is.

Josh Kupershmidt

I broke this in commit 337b6f5e, which
among other things arranged for quicksorts to CHECK_FOR_INTERRUPTS()
slightly less frequently.  Sadly, it also arranged for heapsorts to
CHECK_FOR_INTERRUPTS() much less frequently.  Repair.

Instead of just stopping after removing an arbitrary subset of orphaned
large objects, commit and start a new transaction after each -l objects.
This is just as effective as the original patch at limiting the number of
locks used, and it doesn't require doing the OID collection process
repeatedly to get everything.  Since the option no longer changes the
fundamental behavior of vacuumlo, and it avoids a known server-side
limitation, enable it by default (with a default limit of 1000 LOs per
transaction).

In passing, be more careful about properly quoting the names of tables
and fields, and do some other cosmetic cleanup.

The old code was using exit_horribly or die_horribly other depending on
whether it had an ArchiveHandle on which to close the connection or not;
but there were places that were passing a NULL ArchiveHandle to
die_horribly, and other places that used exit_horribly while having an
AH available.  So there wasn't all that much consistency.

Improve the situation by keeping only one of the routines, and instead
of having to pass the AH down from the caller, arrange for it to be
present for an on_exit_nicely callback to operate on.

Author: Joachim Wieland
Some tweaks by me

Per a suggestion from Robert Haas, in the ongoing "parallel pg_dump"
saga.

I should have done this in b93f5a56 but
didn't notice the problem at the time.

Per report from Marco Nenciarini

This was for demonstration only, and now it was creating compiler
warnings from zlib without an obvious fix (see also
d923125b), let's just remove it.  The
"directory" format is presumably similar enough anyway.

Making this operation look like a utility statement seems generally a good
idea, and particularly so in light of the desire to provide command
triggers for utility statements.  The original choice of representing it as
SELECT with an IntoClause appendage had metastasized into rather a lot of
places, unfortunately, so that this patch is a great deal more complicated
than one might at first expect.

In particular, keeping EXPLAIN working for SELECT INTO and CREATE TABLE AS
subcommands required restructuring some EXPLAIN-related APIs.  Add-on code
that calls ExplainOnePlan or ExplainOneUtility, or uses
ExplainOneQuery_hook, will need adjustment.

Also, the cases PREPARE ... SELECT INTO and CREATE RULE ... SELECT INTO,
which formerly were accepted though undocumented, are no longer accepted.
The PREPARE case can be replaced with use of CREATE TABLE AS EXECUTE.
The CREATE RULE case doesn't seem to have much real-world use (since the
rule would work only once before failing with "table already exists"),
so we'll not bother with that one.

Both SELECT INTO and CREATE TABLE AS still return a command tag of
"SELECT nnnn".  There was some discussion of returning "CREATE TABLE nnnn",
but for the moment backwards compatibility wins the day.

Andres Freund and Tom Lane

This bug was introduced while refactoring in commit 1631598e --- no need
to back-patch.

Bug report and fix from Joachim Wieland.

Failing to do so causes trigger invocation to fail when they are nested
within a function invocation that changes the current package.

Backpatch to 9.1; previous releases used a different method to obtain
_TD.  Per bug report from Mark Murawski (bug #6511)

Author: Alex Hunsaker

the non-development install.  Instead, use the LOAD mechanism to check
for the pg_upgrade_support shared object, like we do for other shared
object checks.

Backpatch to 9.1.

Report from Àlvaro

When converting source files, pg_regress' inputdir and outputdir options were
ignored when computing the locations of the destination files. In consequence,
these options were effectively unusable when the regression inputs need to
be adjusted by pg_regress. This patch makes pg_regress put the converted files
in the same place that these options specify non-converted input or results
files are to be found. Backpatched to all live branches.

suggested by Josh Berkus

optimizer statistics so the cluster can be made available sooner.

When using connection info arrays with a conninfo string in the dbname
slot, some memory would be leaked if an error occurred while
processing the following array slots.

found by Coverity

Since mbvalidate() can alter the string it validates, having the
callers claim that the strings they accept are const is inappropriate.

An invalid combination of pg_cast.castfunc and pg_cast.castmethod
would result in a segmentation fault.  Now it prints a warning.

found by Coverity

found by Coverity

Just for consistency with the other code paths.

found by Coverity

For a little while there I thought match_pathkeys_to_index() was broken
because it wasn't trying to match index columns to pathkeys in order.
Actually that's correct, because GiST can support ordering operators
on any random collection of index columns, but it sure needs a comment.

In commit 57664ed2 I tried to fix a bug
reported by Teodor Sigaev by making non-simple-Var output columns distinct
(by wrapping their expressions with dummy PlaceHolderVar nodes).  This did
not work too well.  Commit b28ffd0f fixed
some ensuing problems with matching to child indexes, but per a recent
report from Claus Stadler, constraint exclusion of UNION ALL subqueries was
still broken, because constant-simplification didn't handle the injected
PlaceHolderVars well either.  On reflection, the original patch was quite
misguided: there is no reason to expect that EquivalenceClass child members
will be distinct.  So instead of trying to make them so, we should ensure
that we can cope with the situation when they're not.

Accordingly, this patch reverts the code changes in the above-mentioned
commits (though the regression test cases they added stay).  Instead, I've
added assorted defenses to make sure that duplicate EC child members don't
cause any problems.  Teodor's original problem ("MergeAppend child's
targetlist doesn't match MergeAppend") is addressed more directly by
revising prepare_sort_from_pathkeys to let the parent MergeAppend's sort
list guide creation of each child's sort list.

In passing, get rid of add_sort_column; as far as I can tell, testing for
duplicate sort keys at this stage is dead code.  Certainly it doesn't
trigger often enough to be worth expending cycles on in ordinary queries.
And keeping the test would've greatly complicated the new logic in
prepare_sort_from_pathkeys, because comparing pathkey list entries against
a previous output array requires that we not skip any entries in the list.

Back-patch to 9.1, like the previous patches.  The only known issue in
this area that wasn't caused by the ill-advised previous patches was the
MergeAppend planning failure, which of course is not relevant before 9.1.
It's possible that we need some of the new defenses against duplicate child
EC entries in older branches, but until there's some clear evidence of that
I'm going to refrain from back-patching further.

This is intended as infrastructure to allow sepgsql to cooperate with
connection pooling software, by allowing the effective security label
to be set for each new connection.

KaiGai Kohei, reviewed by Yeb Havinga.

The tzn value might come from tm->tm_zone, which libc declares as
const, so it's prudent that the upper layers know about this as well.

Use an explicit argument to tell whether to include the time zone in
the output, rather than using some undocumented pointer magic.

found by Coverity

This is for tools such as Coverity that don't know that the grammar
enforces that the case of not having a relation (but instead a query)
cannot happen in the FROM case.

It was already checking for invalid data after "BACKUP FROM", but
would possibly crash if "BACKUP FROM" was missing altogether.

found by Coverity

Although we often don't care about freeing all memory in pg_dump,
these functions already freed the same memory in other code paths, so
we might as well do it consistently.

found by Coverity