Minor improvements for CHECK NO INHERIT documentation.

Fix typo spotted by Thom Brown, and improve wording in another area
where Thom spotted a typo.
Reduce hash size for compute_array_stats, compute_tsvector_stats.

The size is only a hint, but a big hint chews up a lot of memory without
apparently improving performance much.

Analysis and patch by Noah Misch.
Rearrange lazy_scan_heap to avoid visibility map race conditions.

We must set the visibility map bit before releasing our exclusive lock
on the heap page; otherwise, someone might clear the heap page bit
before we set the visibility map bit, leading to a situation where the
visibility map thinks the page is all-visible but it's really not.

This problem has existed since 8.4, but it wasn't critical before we
had index-only scans, since the worst case scenario was that the page
wouldn't get vacuumed until the next scan_all vacuum.

Along the way, a couple of minor, related improvements: (1) if we
pause the heap scan to do an index vac cycle, release any visibility
map page we're holding, since really long-running pins are not good
for a variety of reasons; and (2) warn if we see a page that's marked
all-visible in the visibility map but not on the page level, since
that should never happen any more (it was allowed in previous
releases, but not in 9.2).
Lots of doc corrections.

Josh Kupershmidt
Another typographical correction.

Noted by Guillaume Smet.
Casts to or from a domain type are ignored; warn and document.

Prohibiting this outright would break dumps taken from older versions
that contain such casts, which would create far more pain than is
justified here.

Per report by Jaime Casanova and subsequent discussion.
Fix minor stylistic issue
entab: Improve makefile

A few simplifications and stylistic improvements, found while grepping
around for makefile problems elsewhere.
Standardize indentation of XSL files

Predominant standard is two spaces, so adjust outliers to that.
PL/Python: Improve error messages
Another trivial comment-typo fix.
Remove prototype for nonexistent function.
Fix edge-case behavior of pg_next_dst_boundary().

Due to rather sloppy thinking (on my part, I'm afraid) about the
appropriate behavior for boundary conditions, pg_next_dst_boundary() gave
undefined, platform-dependent results when the input time is exactly the
last recorded DST transition time for the specified time zone, as a result
of fetching values one past the end of its data arrays.

Change its specification to be that it always finds the next DST boundary
*after* the input time, and adjust code to match that.  The sole existing
caller, DetermineTimeZoneOffset, doesn't actually care about this
distinction, since it always uses a probe time earlier than the instant
that it does care about.  So it seemed best to me to change the API to make
the result=1 and result=0 cases more consistent, specifically to ensure
that the "before" outputs always describe the state at the given time,
rather than hacking the code to obey the previous API comment exactly.

Per bug #6605 from Sergey Burladyan.  Back-patch to all supported versions.
Fix planner's handling of RETURNING lists in writable CTEs.

setrefs.c failed to do "rtoffset" adjustment of Vars in RETURNING lists,
which meant they were left with the wrong varnos when the RETURNING list
was in a subquery.  That was never possible before writable CTEs, of
course, but now it's broken.  The executor fails to notice any problem
because ExecEvalVar just references the ecxt_scantuple for any normal
varno; but EXPLAIN breaks when the varno is wrong, as illustrated in a
recent complaint from Bartosz Dmytrak.

Since the eventual rtoffset of the subquery is not known at the time
we are preparing its plan node, the previous scheme of executing
set_returning_clause_references() at that time cannot handle this
adjustment.  Fortunately, it turns out that we don't really need to do it
that way, because all the needed information is available during normal
setrefs.c execution; we just have to dig it out of the ModifyTable node.
So, do that, and get rid of the kluge of early setrefs processing of
RETURNING lists.  (This is a little bit of a cheat in the case of inherited
UPDATE/DELETE, because we are not passing a "root" struct that corresponds
exactly to what the subplan was built with.  But that doesn't matter, and
anyway this is less ugly than early setrefs processing was.)

Back-patch to 9.1, where the problem became possible to hit.
Modify create_index regression test to avoid intermittent failures.

We have been seeing intermittent buildfarm failures due to a query
sometimes not using an index-only scan plan, because a background
auto-ANALYZE prevented the table's all-visible bits from being set
immediately, thereby causing the estimated cost of an index-only scan
to go up considerably.  Adjust the test case so that a bitmap index scan is
preferred instead, which serves equally well for the purpose the test case
is actually meant for.  (Of course, it would be better to eliminate the
interference from auto-ANALYZE, but I see no low-risk way to do that,
so any such fix will have to be left for 9.3 or later.)
psql: Tab completion updates

Add/complete support for:

- ALTER DOMAIN / VALIDATE CONSTRAINT
- ALTER DOMAIN / RENAME
- ALTER DOMAIN / RENAME CONSTRAINT
- ALTER TABLE / RENAME CONSTRAINT
PL/Python: Accept strings in functions returning composite types

Before 9.1, PL/Python functions returning composite types could return
a string and it would be parsed using record_in.  The 9.1 changes made
PL/Python only expect dictionaries, tuples, or objects supporting
getattr as output of composite functions, resulting in a regression
and a confusing error message, as the strings were interpreted as
sequences and the code for transforming lists to database tuples was
used.  Fix this by treating strings separately as before, before
checking for the other types.

The reason why it's important to support string to database tuple
conversion is that trigger functions on tables with composite columns
get the composite row passed in as a string (from record_out).
Without supporting converting this back using record_in, this makes it
impossible to implement pass-through behavior for these columns, as
PL/Python no longer accepts strings for composite values.

A better solution would be to fix the code that transforms composite
inputs into Python objects to produce dictionaries that would then be
correctly interpreted by the Python->PostgreSQL counterpart code.  But
that would be too invasive to backpatch to 9.1, and it is too late in
the 9.2 cycle to attempt it.  It should be revisited in the future,
though.

Reported as bug #6559 by Kirill Simonov.

Jan Urbański
Fix oversight in recent parameterized-path patch.

bitmap_scan_cost_est() has to be able to cope with a BitmapOrPath, but
I'd taken a shortcut that didn't work for that case.  Noted by Heikki.
Add some regression tests since this area is evidently under-covered.
Improve documentation around historical calendar rules.

Get rid of section 8.5.6 (Date/Time Internals), which appears to confuse
people more than it helps, and anyway discussion of Postgres' internal
datetime calculation methods seems pretty out of place here.  Instead,
make datatype.sgml just say that we follow the Gregorian calendar (a bit
of specification not previously present anywhere in that chapter :-()
and link to the History of Units appendix for more info.  Do some mild
editorialization on that appendix, too, to make it clearer that we are
following proleptic Gregorian calendar rules rather than anything more
historically accurate.

Per a question from Florence Cousin and subsequent discussion in
pgsql-docs.
Prevent index-only scans from returning wrong answers under Hot Standby.

The alternative of disallowing index-only scans in HS operation was
discussed, but the consensus was that it was better to treat marking
a page all-visible as a recovery conflict for snapshots that could still
fail to see XIDs on that page.  We may in the future try to soften this,
so that we simply force index scans to do heap fetches in cases where
this may be an issue, rather than throwing a hard conflict.