when we are waiting for old snapshots to go away during a concurrent index
build.  In particular, this rule lets us avoid waiting for
idle-in-transaction sessions.

This logic could be improved further if we had some way to wake up when
the session we are currently waiting for goes idle-in-transaction.  However
that would be a significantly more complex/invasive patch, so it'll have to
wait for some other day.

Simon Riggs, with some improvements by Tom.

interval_eq() considers equal.  I'm not sure how that fundamental requirement
escaped us through multiple revisions of this hash function, but there it is;
it's been wrong since interval_hash was first written for PG 7.1.
Per bug #4748 from Roman Kononov.

Backpatch to all supported releases.

This patch changes the contents of hash indexes for interval columns.  That's
no particular problem for PG 8.4, since we've broken on-disk compatibility
of hash indexes already; but it will require a migration warning note in
the next minor releases of all existing branches: "if you have any hash
indexes on columns of type interval, REINDEX them after updating".

To implement this without almost duplicating the reloption table, treat
relopt_kind as a bitmask instead of an integer value.  This decreases the
range of allowed values, but it's not clear that there's need for that much
values anyway.

This patch also makes heap_reloptions explicitly a no-op for relation kinds
other than heap and TOAST tables.

Patch by ITAGAKI Takahiro with minor edits from me.  (In particular I removed
the bit about adding relation kind to an error message, which I intend to
commit separately.)

TOAST tables and indexes; to wit, never show either.  (You can
examine them with plain \d if you're really so inclined.)

Windows without that, but we shouldn't put bad examples where people might
copy them.  Also, reformat slightly to improve the odds that pgindent
won't go nuts on this.

try to protect an already-existing buffer from being evicted.  This was
left as an open issue when the posix_fadvise patch was committed.  I'm
not sure there's any evidence to justify more work in this area, but we
should have some record about it in the source code.

for its arguments.  Also add a regression test, since someone apparently
changed every single plpython test case to use only named parameters; else
we'd have noticed this sooner.

Euler Taveira de Oliveira, per a report from Alvaro

This method will not catch all different ways since the locale
handling in NTFS doesn't provide an easy way to do that, but it
will hopefully solve the most common cases causing startup
problems when the backend is found in the system PATH.

Attempts to fix bug #4694.

ineffective posix_fadvise().

for simple Var targetlist entries all the time, even when there are other
entries that are not simple Vars.  Also, ensure that we prefetch attributes
(with slot_getsomeattrs) for all Vars in the targetlist, even those buried
within expressions.  In combination these changes seem to significantly
reduce the runtime for cases where tlists are mostly but not exclusively
Vars.  Per my proposal of yesterday.

"effective_io_concurrency" on systems without posix_fadvise().

Andrew Gierth

Robert Lor

Per "maosen.zhang" <maosen.zhang@alibaba-inc.com> report.

specified.

Martin Pihlak

conversion functions.  This allows transaction rollback to revert to a
previous client_encoding setting without doing fresh catalog lookups.
I believe that this explains and fixes the recent report of "failed to commit
client_encoding" failures.

This bug is present in 8.3.x, but it doesn't seem prudent to back-patch
the fix, at least not till it's had some time for field testing in HEAD.

In passing, remove SetDefaultClientEncoding(), which was used nowhere.

we failed to assign, even in "can't happen" cases.  Motivated by wondering
what's going on in a recent trouble report where "failed to commit" did
happen.

casting effort whenever the input value was NULL.  However this prevents
application of not-null domain constraints in the cases that use this
function, as illustrated in bug #4741.  Since this function isn't meant
for use in performance-critical paths anyway, this certainly seems like
another case of "premature optimization is the root of all evil".

Back-patch as far as 8.2; older versions made no effort to enforce
domain constraints here anyway.

when there are many blobs and not so many comments.  Tamas Vincze

per-database settings.

temporary tables of other sessions; that is unsafe because of the way our
buffer management works.  Per report from Stuart Bishop.
This is redundant with the bufmgr.c checks in HEAD, but not at all redundant
in the back branches.

at the top of their sections.

temp relations; this is no more expensive than before, now that we have
pg_class.relistemp.  Insert tests into bufmgr.c to prevent attempting
to fetch pages from nonlocal temp relations.  This provides a low-level
defense against bugs-of-omission allowing temp pages to be loaded into shared
buffers, as in the contrib/pgstattuple problem reported by Stuart Bishop.
While at it, tweak a bunch of places to use new relcache tests (instead of
expensive probes into pg_namespace) to detect local or nonlocal temp tables.

Give an error message and exit instead, like we do elsewhere...

Per report from Wez Furlong and Robert Treat.

relations (including a temp table's indexes and toast table/index), and
false for normal relations.  For ease of checking, this commit just adds
the column and fills it correctly --- revising the relation access machinery
to use it will come separately.

at the same instant as a new backend is spawned. Since CountActiveBackends()
doesn't hold ProcArrayLock, it needs to be prepared for the case that a
pointer at the end of the proc array is still NULL even though numProcs says
it should be valid, since it doesn't hold ProcArrayLock. Backpatch to 8.1.
8.0 and earlier had this right, but it was broken in the split of PGPROC and
sinval shared memory arrays.

Per report and proposal by Marko Kreen.

but not OpenSSL (or perhaps vice versa, if that's possible).

Andrew Chernow, with minor editorialization by me.