It appears that this will be faster for all but the shortest strings;
at least one some platforms, memcmp() can use word-at-a-time comparisons.

Noah Misch, somewhat pared down.

Andreas Karlsson

On MacOS X, and apparently also on other BSD-derived systems, attaching
a debugger causes getppid() to return the pid of the debugging process
rather than the actual parent PID.  As a result, debugging the
autovacuum launcher, startup process, or WAL sender on such systems
causes it to exit, because the previous coding of PostmasterIsAlive()
detects postmaster death by testing whether getppid() == PostmasterPid.

Work around that behavior by checking the return value of getppid()
more carefully.  If it's PostmasterPid, the postmaster must be alive;
if it's 1, assume the postmaster is dead.  If it's any other value,
assume we've been debugged and fall through to the less-reliable
kill() test.

Review by Tom Lane.

This case can arise if a transaction has written data, but only to
temporary tables.  Loss of the commit record in case of a crash won't
matter, because the temporary tables will be lost anyway.

Reviewed by Heikki Linnakangas and Simon Riggs.

Jaime Casanova

Since we're not multithreaded it only provides marginally useful
information, and it does require a newer version of the Platform SDK
than we target. We may want to reconsider this in the future along
with a fix for MinGW.

eval_const_expressions() can replace CaseTestExprs with constants when
the surrounding CASE's test expression is a constant.  This confuses
ruleutils.c's heuristic for deparsing simple-form CASEs, leading to
Assert failures or "unexpected CASE WHEN clause" errors.  I had put in
a hack solution for that years ago (see commit
514ce7a3 of 2006-10-01), but bug #5794
from Peter Speck shows that that solution failed to cover all cases.

Fortunately, there's a much better way, which came to me upon reflecting
that Peter's "CASE TRUE WHEN" seemed pretty redundant: we can "simplify"
the simple-form CASE to the general form of CASE, by simply omitting the
constant test expression from the rebuilt CASE construct.  This is
intuitively valid because there is no need for the executor to evaluate
the test expression at runtime; it will never be referenced, because any
CaseTestExprs that would have referenced it are now replaced by constants.
This won't save a whole lot of cycles, since evaluating a Const is pretty
cheap, but a cycle saved is a cycle earned.  In any case it beats kluging
ruleutils.c still further.  So this patch improves const-simplification
and reverts the previous change in ruleutils.c.

Back-patch to all supported branches.  The bug exists in 8.1 too, but it's
out of warranty.

After parsing a parenthesized subexpression, we must pop all pending
ANDs and NOTs off the stack, just like the case for a simple operand.
Per bug #5793.

Also fix clones of this routine in contrib/intarray and contrib/ltree,
where input of types query_int and ltxtquery had the same problem.

Back-patch to all supported versions.

Add support for collecting "minidump" style crash dumps on
Windows, by setting up an exception handling filter. Crash
dumps will be generated in PGDATA/crashdumps if the directory
is created (the existance of the directory is used as on/off
switch for the generation of the dumps).

Craig Ringer and Magnus Hagander

connections when the server is down, on Win32.

Make the variables visible (but not used) even when
support is not compiled in.

This improves tag output by log_line_prefix

If there's no work to be done, just exit quickly, before initialization.

This prevents the word "waiting" from briefly disappearing from the ps
status line when ResolveRecoveryConflictWithVirtualXIDs begins a new
iteration of the outer loop.

Along the way, remove some useless pgstat_report_waiting() calls;
the startup process doesn't appear in pg_stat_activity.

Fujii Masao

Per report from Fujii Masao, and subsequent discussion.

These comments were not updated when we added the EXEC_BACKEND
mechanism for Windows, even though it rendered them inaccurate.

Also unify two unnecessarily-separate #ifdef __alpha code blocks.

We don't actually need optreset, because we can easily fix the code to
ensure that it's cleanly restartable after having completed a scan over the
argv array; which is the only case we need to restart in.  Getting rid of
it avoids a class of interactions with the system libraries and allows
reversion of my change of yesterday in postmaster.c and postgres.c.

Back-patch to 8.4.  Before that the getopt code was a bit different anyway.

libpq connection, per report from Magnus.  This happens only on GIT
master and only on Win32 because that is the platform where "" maps to
an IP address (localhost).

The mingw people don't appear to care about compatibility with non-GNU
versions of getopt, so force use of our own copy of getopt on Windows.
Also, ensure that we make use of optreset when using our own copy.

Per report from Andrew Dunstan.  Back-patch to all versions supported
on Windows.

This patch replaces Guttman's generalized split method with a simple
sort-by-center-points algorithm.  Since the data is only one-dimensional
we don't really need the slow and none-too-stable Guttman method.

This is in part a bug fix, since seg has the same size_alpha versus
size_beta typo that was recently fixed in contrib/cube.  It seems
prudent to apply this rather aggressive fix only in HEAD, though.
Back branches will just get the typo fix.

Alexander Korotkov, reviewed by Yeb Havinga

One of the usages of the binary version is to read files in a different
encoding from the server encoding.

Dimitri Fontaine and Itagaki Takahiro.

documentation.  (Many were left over from the old pg_migrator naming.)

Greg Smith, reviewed by Jeff Janes

Allow INSERT INTO, UPDATE, and DELETE FROM to be completed with
either the name of a table (as before) or the name of a view with
an appropriate INSTEAD OF rule.

Along the way, allow CREATE TRIGGER to be completed with INSTEAD OF,
as well as BEFORE and AFTER.

David Fetter, reviewed by Itagaki Takahiro

This is intended as infrastructure to allow an eventual SE-Linux plugin to
support trusted procedures.

KaiGai Kohei

Noted by Tom Lane.

Fiji and Samoa.  Historical corrections for Hong Kong.

This commit replaces pg_class.relistemp with pg_class.relpersistence;
and also modifies the RangeVar node type to carry relpersistence rather
than istemp.  It also removes removes rd_istemp from RelationData and
instead performs the correct computation based on relpersistence.

For clarity, we add three new macros: RelationNeedsWAL(),
RelationUsesLocalBuffers(), and RelationUsesTempNamespace(), so that we
can clarify the purpose of each check that previous depended on
rd_istemp.

This is intended as infrastructure for the upcoming unlogged tables
patch, as well as for future possible work on global temporary tables.

We were failing to zero out some pg_stat_database counters that have
been added since the initial pgstats coding.  This is a bug, but not
back-patching the fix since changing this behavior in a minor release
seems a cure worse than the disease.

Report and patch by Tomas Vondra.

(Hm, I wonder whether BCC defines them either...)

Also label dangling endifs a bit better in this area.

1. Don't reimplement S_ISDIR() and S_ISREG() badly.
2. Don't reimplement access() badly.

This code appears to have been copied from ancient versions of the
corresponding backend routines, and not patched to incorporate subsequent
fixes (see my commits of 2008-03-31 and 2010-01-14 respectively).
It might be a good idea to change it to just *call* those routines,
but for now I'll just transpose these fixes over.