Add documentation.

Supports migration from PG 8.3 and 8.4.

Argentina, Australian Antarctic, Bangladesh, Mexico, Morocco, Pakistan,
Palestine, Russia, Syria, Tunisia.  Historical corrections for Taiwan.

Per discussion, if we have PKT in there then PKST should be too.
Also, fix mistaken claim that these abbrevs are not known to zic.

Fixes a complaint from src/tools/pginclude/cpluspluscheck reported by
Peter Eisentraut.

archive_command) as soon as possible, namely just before issuing a new call
of archive_command, even when there is a backlog of files to be archived.
The original coding would only absorb new settings after clearing the backlog
and returning to the outer loop.  Per discussion.

Back-patch to 8.3.  The logic in prior versions is a bit different and it
doesn't seem worth taking any risks of breaking it.

As suggested by Andy Lester.

tables --- the parent table no longer got checked, either.  Per bug #5458
from Takahiro Itagaki.

Now validators work properly even when the settings contain
parameters that affect behavior of the function, like search_path.

Reported by Erwin Brandstetter.

MIN or MAX, we must take care to insert the added qual in a legal place among
the existing indexquals, if any.  The btree index AM requires the quals to
appear in index-column order.  We didn't have to worry about this before
because "target IS NOT NULL" was just treated as a plain scan filter condition;
but as of 9.0 it can be an index qual and then it has to follow the rule.
Per report from Ian Barwick.

Noted by KOIZUMI Satoru.

My initial impression that glibc was measuring the precision in characters
(which is what the Linux man page says it does) was incorrect.  It does take
the precision to be in bytes, but it also tries to truncate the string at a
character boundary.  The bottom line remains the same: it will mess up
if the string is not in the encoding it expects, so we need to avoid %.*s
anytime there's a significant risk of that.  Previous code changes are still
good, but adjust the comments to reflect this knowledge.  Per research by
Hernan Gonzalez.

Depending on which spec you read, field widths and precisions in %s may be
counted either in bytes or characters.  Our code was assuming bytes, which
is wrong at least for glibc's implementation, and in any case libc might
have a different idea of the prevailing encoding than we do.  Hence, for
portable results we must avoid using anything more complex than just "%s"
unless the string to be printed is known to be all-ASCII.

This patch fixes the cases I could find, including the psql formatting
failure reported by Hernan Gonzalez.  In HEAD only, I also added comments
to some places where it appears safe to continue using "%.*s".

ECPG connect routine only checked for NULL to find empty parameters, but user and password can also be "".

This should allow LD_LIBRARY_PATH to work as desired.  Per trouble
report from Andy Colson.

refers to itself (directly or indirectly).  Instead, print a message when
recursion is detected, and don't expand the repeated reference.  Per bug
#5448 from Francis Markham.

Back-patch to 8.0.  Although the issue exists in 7.4 as well, it seems
impractical to fix there because of the lack of any state stack that
could be used to track active expansions.

minRecoveryPoint in control file when replaying a parameter change record,
to ensure that we don't allow hot standby on WAL generated without
wal_level='hot_standby' after a standby restart.

form a hierarchy. Per Simon's suggestion.

what "eventually consistent" means.

the PITR documentation to mention that you need to set wal_level to
'archive' or 'hot_standby', to enable WAL archiving. Per Simon's request.

field of the WAL record.  The previous coding always wrote to the main fork,
resulting in data corruption if the page was meant to go into a non-default
fork.

At present, the only operation that can produce such WAL records is
ALTER TABLE/INDEX SET TABLESPACE when executed with archive_mode = on.
Data corruption would be observed on standby slaves, and could occur on the
master as well if a database crash and recovery occurred after committing
the ALTER and before the next checkpoint.  Per report from Gordon Shannon.

Back-patch to 8.4; the problem doesn't exist in earlier branches because
we didn't have a concept of multiple relation forks then.

to tests and no changes in accepted server behaviour.

for all other parameters where the default is expressed in a different unit.

MaxStandbyDelay.  Use the GUC units mechanism for the value, and choose more
appropriate timestamp functions for performing tests with it.  Make the
ps_activity manipulation in ResolveRecoveryConflictWithVirtualXIDs have
behavior similar to ps_activity code elsewhere, notably not updating the
display when update_process_title is off and not truncating the display
contents at an arbitrarily-chosen length.  Improve the docs to be explicit
about what MaxStandbyDelay actually measures, viz the difference between
primary and standby servers' clocks, and the possible hazards if their clocks
aren't in sync.

returns EINVAL for an existing shared memory segment.  Although it's not
terribly sensible, that behavior does meet the POSIX spec because EINVAL
is the appropriate error code when the existing segment is smaller than the
requested size, and the spec explicitly disclaims any particular ordering of
error checks.  Moreover, it does in fact happen on OS X and probably other
BSD-derived kernels.  (We were able to talk NetBSD into changing their code,
but purging that behavior from the wild completely seems unlikely to happen.)
We need to distinguish collision with a pre-existing segment from invalid size
request in order to behave sensibly, so it's worth some extra code here to get
it right.  Per report from Gavin Kistner and subsequent investigation.

Back-patch to all supported versions, since any of them could get used
with a kernel having the debatable behavior.

It appears that gmake gets confused if postgres.sgml is not present in
the working directory, and instantiates some default rule or other that
would let postgres.sgml be built from postgres.xml.  I haven't been able
to track down exactly where that's coming from, but the problem can be
dodged by specifying srcdir explicitly in the rule for postgres.xml.
Per report from Vladimir Kokovic.

The previous coding had it in a pipe, which on most shells won't report
the error.  Per experimentation with a bug report from Vladimir Kokovic.
This doesn't actually fix his problem, but it does explain why make
didn't report that there was a problem.

Per report from Andres Freund.

possible to set most of the SHM kernel parameters without a reboot.
Also, reorder the paragraph to explain the modern configuration method first.
There are probably not too many people who still care about how to do it on
OS X 10.3 or older.

child tables.  Per gripe from Jaime Casanova.

memory if the result had zero rows, and also if there was any sort of error
while converting the result tuples into Python data.  Reported and partially
fixed by Andres Freund.

Back-patch to all supported versions.  Note: I haven't tested the 7.4 fix.
7.4's configure check for python is so obsolete it doesn't work on my
current machines :-(.  The logic change is pretty straightforward though.

This is mostly to suppress compiler warnings, although in principle
the cases could result in undesirable behavior.

Martin Pitt

and add missing code in btree_desc for them. This fixes the bug
with "tree_redo: unknown op code 208" error reported by Jaime Casanova.