Introduce less-bogus handling of collations in contrib/postgres_fdw.

Treat expressions as being remotely executable only if all collations used
in them are determined by Vars of the foreign table.  This means that, if
the foreign server gets different answers than we do, it's the user's fault
for not having marked the foreign table columns with collations equivalent
to the remote table's.  This rule allows most simple expressions such as
"var < 'constant'" to be sent to the remote side, because the constant
isn't determining the collation (the Var's collation would win).  There's
still room for improvement, but it's hard to see how to do it without a
lot more knowledge and/or assumptions about what the remote side will do.
Fix bug in dumping prior releases due to MV REFRESH dependency checking.

Reports and suggested patches from Fujii Masao and Andrew Dunstan.

Andrew Dunstan
Add regression tests for XML mapping of domains

Pavel Stěhule
Add cost estimation of range @> and <@ operators.

The estimates are based on the existing lower bound histogram, and a new
histogram of range lengths.

Bump catversion, because the range length histogram now needs to be present
in statistic slot kind 6, or you get an error on @> and <@ queries. (A
re-ANALYZE would be enough to fix that, though)

Alexander Korotkov, with some refactoring by me.
Change the way UESCAPE is lexed, to reduce the size of the flex tables.

The error rule used to avoid backtracking with the U&'...' UESCAPE 'x'
syntax bloated the flex tables, so refactor that. This patch makes the error
rule shorter, by introducing a new exclusive flex state that's entered after
parsing U&'...'. This shrinks the postgres binary by about 220kB.
Avoid inserting Result nodes that only compute identity projections.

The planner sometimes inserts Result nodes to perform column projections
(ie, arbitrary scalar calculations) above plan nodes that lack projection
logic of their own.  However, we did that even if the lower plan node was
in fact producing the required column set already; which is a pretty common
case given the popularity of "SELECT * FROM ...".  Measurements show that
the useless plan node adds non-negligible overhead, especially when there
are many columns in the result.  So add a check to avoid inserting a Result
node unless there's something useful for it to do.

There are a couple of remaining places where unnecessary Result nodes
could get inserted, but they are (a) much less performance-critical,
and (b) coded in such a way that it's hard to avoid inserting a Result,
because the desired tlist is changed on-the-fly in subsequent logic.
We'll leave those alone for now.

Kyotaro Horiguchi; reviewed and further hacked on by Amit Kapila and
Tom Lane.
Minor fixes for hstore_to_json_loose().

Fix unportable use of isdigit(), get rid of useless calculations.
Also update psqlscan.l with the UESCAPE error rule changes.

Even though this patch had no user-visible difference, better keep the code
in psqlscan.l sync with the backend lexer. And of course it's nice to shrink
the psql binary, too. Ecpg's version of the lexer doesn't have the error
rule, it doesn't try to avoid backing up, so it doesn't need to be modified.

As reminded by Tom Lane
Add regression test for MV join to view.

This would have caught a bug in the initial patch, and seems like
a good thing to test going forward.

Per bug report by Erik Rijkers and fix by Tom Lane
Revert unnecessary change in MV call to checkRuleResultList().

Due to a misreading of the function's comment block, there was an
unneeded change to a call in rewriteDefine.c.  There is, in fact
no reason to pass false for a MV; it should be true just like a
view.

Fixes issue pointed out by Tom Lane
Avoid inserting no-op Limit plan nodes.

This was discussed in connection with the patch to avoid inserting no-op
Result nodes, but not actually implemented therein.
Extend format() to handle field width and left/right alignment.

This change adds some more standard sprintf() functionality to format().

Pavel Stehule, reviewed by Dean Rasheed and Kyotaro Horiguchi
Improve error reporting in code that checks for buffer refcount leaks.

Formerly we just Assert'ed that each refcount was zero, which was quick
and easy but failed to provide a good overview of what was wrong.
Change the code so that we'll call PrintBufferLeakWarning() for each
buffer with a nonzero refcount, and then Assert at the end of the loop.
This costs nothing in runtime and might ease diagnosis of some bugs.

Greg Smith, reviewed by Satoshi Nagayasu, further tweaked by me
Improve the documentation about commit_delay.

Clarify the docs explaining what commit_delay does, and add a
recommendation about a useful value for it, namely half of the single-page
fsync time reported by pg_test_fsync.  This is informed by testing of
the new-in-9.3 implementation of commit_delay; in prior versions it
was far harder to arrive at a useful setting.

In passing, do some wordsmithing and markup-fixing in the same general
area.

Also, change pg_test_fsync's default time-per-test from 2 seconds to 5.
The old value was about the minimum at which the results could be taken
seriously at all, and so seems a tad optimistic as a default.

Peter Geoghegan, reviewed by Noah Misch; some additional editing by me
pg_controldata: Undo message spelling change
pg_resetxlog: Capitalize placeholder in --help output
Add lock_timeout configuration parameter.

This GUC allows limiting the time spent waiting to acquire any one
heavyweight lock.

In support of this, improve the recently-added timeout infrastructure
to permit efficiently enabling or disabling multiple timeouts at once.
That reduces the performance hit from turning on lock_timeout, though
it's still not zero.

Zoltán Böszörményi, reviewed by Tom Lane,
Stephen Frost, and Hari Babu