The initial coding just descended the index if any of the target trigrams
were possibly present at the next level down.  But actually we can apply
trigramsMatchGraph() so as to take advantage of AND requirements when there
are some.  The input data might contain false positive matches, but that
can only result in a false positive result, not false negative, so it's
safe to do it this way.

Alexander Korotkov

This changes the behavior of the start and stop actions to exit
successfully if the server was already started or stopped.

This changes the default behavior of the start action:  Before, if the
server was already running, it would print a message and succeed.  Now,
that situation will result in an error.  When running in idempotent
mode, no message is printed and pg_ctl exits successfully.

It was considered to just make the idempotent behavior the default and
only option, but pg_upgrade needs the old behavior.

The build of .pc (pkg-config) files depends on all makefiles in use, and
in dependency tracking mode, the previous coding ended up including
/dev/null as a makefile.  Apparently, on some platforms the modification
time of /dev/null changes sporadically, and so the .pc files would end
up being rebuilt every so often.  Fix that by changing the makefile code
to do without using /dev/null.

Revert the matview-related changes in explain.c's API, as per recent
complaint from Robert Haas.  The reason for these appears to have been
principally some ill-considered choices around having intorel_startup do
what ought to be parse-time checking, plus a poor arrangement for passing
it the view parsetree it needs to store into pg_rewrite when creating a
materialized view.  Do the latter by having parse analysis stick a copy
into the IntoClause, instead of doing it at runtime.  (On the whole,
I seriously question the choice to represent CREATE MATERIALIZED VIEW as a
variant of SELECT INTO/CREATE TABLE AS, because that means injecting even
more complexity into what was already a horrid legacy kluge.  However,
I didn't go so far as to rethink that choice ... yet.)

I also moved several error checks into matview parse analysis, and
made the check for external Params in a matview more accurate.

In passing, clean things up a bit more around interpretOidsOption(),
and fix things so that we can use that to force no-oids for views,
sequences, etc, thereby eliminating the need to cons up "oids = false"
options when creating them.

catversion bump due to change in IntoClause.  (I wonder though if we
really need readfuncs/outfuncs support for IntoClause anymore.)

per suggestion from Gurjeet Singh

Also fix accessing pgentab binary and tar.

Gurjeet Singh

To do this, we add an additional object access hook type,
OAT_FUNCTION_EXECUTE.

KaiGai Kohei

KaiGai Kohei

KaiGai Kohei, based on a suggestion from Álvaro Herrera

Per report by Will Leinweber and Peter Eisentraut

The old web site link no longer worked, and some information was
outdated.

Remove references to "one click", as we're not supposed to call
them that anymore.

Latch activity was not being detected by non-database-connected workers; the
SIGUSR1 signal handler which is normally in charge of that was set to SIG_IGN.
Create a simple handler to call latch_sigusr1_handler instead.

Robert Haas (bug report and suggested fix)

Add a SignalUnconnectedWorkers() call so that non-database-connected background
workers are also notified when postmaster is SIGHUPped.  Previously, only
database-connected workers were.

Michael Paquier (bug report and fix)

This wasn't addressed in the original patch, but it doesn't take very
much additional code to cover the case, so let's get it done.

Since pg_trgm 1.1 hasn't been released yet, I just changed the definition
of what's in it, rather than inventing a 1.2.

Make use of some GUC variables, and add SIGHUP handling to reload
the config file.  Patch submitted by Guillaume Lelarge.

Also, report to pg_stat_activity.  Per report from Marc Cousin, add
setting of statement start time.

Marti Raudsepp.

Per a note from Dickson S. Guedes.

The intent was that being populated would, long term, be just one
of the conditions which could affect whether a matview was
scannable; being populated should be necessary but not always
sufficient to scan the relation.  Since only CREATE and REFRESH
currently determine the scannability, names and comments
accidentally conflated these concepts, leading to confusion.

Also add missing locking for the SQL function which allows a
test for scannability, and fix a modularity violatiion.

Per complaints from Tom Lane, although its not clear that these
will satisfy his concerns.  Hopefully this will at least better
frame the discussion.

The materialized views patch adjusted ExplainOneQuery to take an
additional DestReceiver argument, but failed to add a matching
argument to the definition of ExplainOneQuery_hook.  This is a
problem for users of the hook that want to call ExplainOnePlan.
Fix by adding the missing argument.

This works by extracting trigrams from the given regular expression,
in generally the same spirit as the previously-existing support for
LIKE searches, though of course the details are far more complicated.

Currently, only GIN indexes are supported.  We might be able to make
it work with GiST indexes later.

The implementation includes adding API functions to backend/regex/
to provide a view of the search NFA created from a regular expression.
These functions are meant to be generic enough to be supportable in
a standalone version of the regex library, should that ever happen.

Alexander Korotkov, reviewed by Heikki Linnakangas and Tom Lane

KeepLogSeg function was broken when we switched to use a 64-bit int for the
segment number.

Per report from Jeff Janes.

Heikki reported comment was wrong, so fixed
code to match the comment: we only need to
take additional locking precautions when we
have a shared lock on the buffer.

We copy the buffer before inserting an XLOG_HINT to avoid WAL CRC errors
caused by concurrent hint writes to buffer while share locked. To make this work
we refactor RestoreBackupBlock() to allow an XLOG_HINT to avoid the normal
path for backup blocks, which assumes the underlying buffer is exclusive locked.
Resulting code completely changes layout of XLOG_HINT WAL records, but
this isn't even beta code, so this is a low impact change.
In passing, avoid taking WALInsertLock for full page writes on checksummed
hints, remove related cruft from XLogInsert() and improve xlog_desc record for
XLOG_HINT.

Andres Freund

Bug report by Fujii Masao, testing by Jeff Janes and Jaime Casanova,
review by Jeff Davis and Simon Riggs. Applied with changes from review
and some comment editing.

From performance analysis by Heikki Linnakangas

In CLUSTER, VACUUM FULL and ALTER TABLE SET TABLESPACE
I erroneously set checksum before log_newpage, which
sets the LSN and invalidates the checksum. So set
checksum immediately *after* log_newpage.

Bug report Fujii Masao, Fix and patch by Jeff Davis

contrib/pg_trgm's make_trigrams() was coded to ignore multibyte character
boundaries and just make trigrams from bytes if USE_WIDE_UPPER_LOWER wasn't
defined.  This is a bit odd, since there's no obvious reason why trigram
compaction rules should depend on the presence of towlower() and friends.
What's more, there was an Assert() that would fail if that code path was
fed any multibyte characters.

We need to do something about this since the pending regex-indexing patch
has an assumption that you get just one "trgm" from any three characters.
The best solution seems to be to remove the USE_WIDE_UPPER_LOWER
dependency, which shouldn't really have been there in the first place.
The second loop in make_trigrams() is now just a fast path and not a
potentially incompatible algorithm.

If there is anybody still using Postgres on machines without wcstombs() or
towlower(), and they have non-ASCII data indexed by pg_trgm, they'll need
to REINDEX those indexes after pg_upgrade to 9.3, else searches may fail
incorrectly. It seems likely that there are no such installations, though.

In passing, rename cnt_trigram to compact_trigram, which seems to better
describe its functionality, and improve make_trigrams' test for whether it
has to use the slow path or not (per a suggestion from Alexander Korotkov).

Per report from Jaime Casanova.  Very curious that no one else has seen
this failure ... but the code is clearly wrong as-is.

KaiGai Kohei, with comment and doc wordsmithing by me

There's been some confusion expressed about this point, so clarify.
Extended version of a patch by David Wheeler.

Counting newlines shows that quite a few recent patches have neglected
to update the output-lines count given to PageOutput().  Fortunately
it's not terribly critical that this be exact, since we long since
exceeded the height of most people's terminal windows.  Still, maybe
we ought to think of a way to not have to maintain this manually anymore.

This allows convenient re-execution of commands.

Will Leinweber, reviewed by Peter Eisentraut, Daniel Farina, and Tom Lane

Bug report by David Wheeler, diagnosis assistance from Tom Lane.

'strdup' the PSQLRC environment variable value before calling a routine
that might free() it.

Backpatch to 9.2, where the bug first appeared.