truncations in FSM code, call FreeSpaceMapTruncateRel from smgr_redo. To
make that cleaner from modularity point of view, move the WAL-logging one
level up to RelationTruncate, and move RelationTruncate and all the
related WAL-logging to new src/backend/catalog/storage.c file. Introduce
new RelationCreateStorage and RelationDropStorage functions that are used
instead of calling smgrcreate/smgrscheduleunlink directly. Move the
pending rel deletion stuff from smgrcreate/smgrscheduleunlink to the new
functions. This leaves smgr.c as a thin wrapper around md.c; all the
transactional stuff is now in storage.c.

This will make it easier to add new forks with similar truncation logic,
like the visibility map.

Actually, it can't but some compilers are not smart enough.
Per Peter Eisentraut gripe.

Sort the output by command name.  This previously only worked by source
file name, which doesn't always match the command name exactly.  And it
certainly won't work for multiple refnames.

table is less abstract.  Most common implementations were already
mentioned in the text.

slow-running queries.

Takahiro Itagaki

somewhat reasonably.  It's not perfect, but it beats the kluge
proposed in the auto-explain patch ...

* Refactor explain.c slightly to export a convenient-to-use subroutine
for printing EXPLAIN results.

* Provide hooks for plugins to get control at ExecutorStart and ExecutorEnd
as well as ExecutorRun.

* Add some minimal support for tracking the total runtime of ExecutorRun.
This code won't actually do anything unless a plugin prods it to.

* Change the API of the DefineCustomXXXVariable functions to allow nonzero
"flags" to be specified for a custom GUC variable.  While at it, also make
the "bootstrap" default value for custom GUCs be explicitly specified as a
parameter to these functions.  This is to eliminate confusion over where the
default comes from, as has been expressed in the past by some users of the
custom-variable facility.

* Refactor GUC code a bit to ensure that a custom variable gets initialized to
something valid (like its default value) even if the placeholder value was
invalid.

Andrew Chernow

getpeerucred() function.

Author: Garick Hamlin <ghamlin@isc.upenn.edu>

conflict resolution.

Performance is increased from 50% up to 10^3 times depending on data.

locate the target row, if the cursor was declared with FOR UPDATE or FOR
SHARE.  This approach is more flexible and reliable than digging through the
plan tree; for instance it can cope with join cursors.  But we still provide
the old code for use with non-FOR-UPDATE cursors.  Per gripe from Robert Haas.

also backpatched to 8.3

return the tableoid as well as the ctid for any FOR UPDATE targets that
have child tables.  All child tables are listed in the ExecRowMark list,
but the executor just skips the ones that didn't produce the current row.

Curiously, this longstanding restriction doesn't seem to have been documented
anywhere; so no doc changes.

procedure support: it's possible to get confused because exported procedures
have two different addresses.  Per Andrew Chernow.

since it's now just a SQL module and no C code.

This continues the saga of trying to get PGDLLIMPORT to work in pg_crc.h
in both backend and frontend environments.

array_agg() and unnest().  We could drop it entirely in the future,
but let's keep it for a release or two as a compatibility assist.

if the user is superuser.  This makes available to extension modules the same
sort of trick being practiced by array_agg().  The reason for the superuser
restriction is that you could crash the system by connecting up an
incompatible pair of internal-using functions as an aggregate.  It shouldn't
interfere with any legitimate use, since you'd have to be superuser to create
the internal-using transition and final functions anyway.

returns VOID.  This is the last of the easy fixes I recommended in
11870.1218838360@sss.pgh.pa.us --- the others got done awhile ago but
I forgot about this one.

before passing it to elog.

entries, we don't have to do two builds here as well.

another section if required by the platform (instead of the old way of
building them in section "l" and always transforming them to the
platform-specific section).

This speeds up the installation on common platforms, and it avoids some
funny business with the man page tools and build process.

a pointer, why don't we just fix that.  Every known use of "internal" really
means a pointer anyway.

heap_form_tuple.  Since this removes the last remaining caller of
heap_addheader, remove it.

Extracted from the column privileges patch from Stephen Frost, with further
code cleanups by me.

anyelement.  This lacks the WITH ORDINALITY option, as well as the multiple
input arrays option added in the most recent SQL specs.  But it's still a
pretty useful subset of the spec's functionality, and it is enough to
allow obsoleting contrib/intagg.

about how this is playing fast and loose with the type system.

and thereby in the pg_timezone_names view.  Although we allow such zones
to be used in certain limited contexts like AT TIME ZONE, we don't allow
them in SET TIME ZONE, and bug #4528 shows that they're more likely to
confuse users than do anything useful.  So hide 'em.  (Note that we don't
even generate these zones when installing our own timezone database.
But they are likely to be present when using a system-provided database.)

for inserting tuples in increasing TID order.  It's not clear whether this
fully explains Ivan Sergio Borgonovo's complaint, but simple testing
confirms that a scan that doesn't start at block 0 can slow GIN build by
a factor of three or four.

Backpatch to 8.3.  Sync scan didn't exist before that.

Rearrange the documentation a bit now that array_agg and xmlagg have similar
semantics and issues.

best of Robert Haas, Jeff Davis, Peter Eisentraut