This is how it was documented originally, but several years ago somebody
decided that DEFAULT isn't a type of constraint.  Well, the grammar thinks
it is.  The documentation was wrong in two ways: it alleged that DEFAULT
had to appear before any other kind of constraint, and it alleged that you
can't prefix a DEFAULT clause with a "CONSTRAINT name" clause, when in fact
you can.  (The latter behavior probably isn't SQL-standard, but our grammar
has always allowed it.)

This patch responds to Fujii Masao's observation that the ALTER TABLE
documentation mistakenly implied that you couldn't include DEFAULT in
ALTER TABLE ADD COLUMN; though this isn't the way he proposed fixing it.

It must be added at the end of the ExecStatusType enum to avoid ABI
breakage compared to previous libpq versions.  Noted by Magnus.

Move the list of what's restricted to superusers into the table
itself, so it doesn't get missed again.

per change to the file for pg_ctl.

My previous commit, 85cff3ce on
2010-12-25, failed to update errcodes.sgml or plerrcodes.h.  This patch
corrects that oversight, per a gripe from Tom Lane, and also corrects
a typographical error.

port and socket directory into postmaster.pid, and have pg_ctl read from
that file, for use by PQping().

The order on the pg_dump/pg_dumpall man pages is not very strict, but
surely putting it under connection options was wrong.

The former is the option actually supported by these commands.

cleanup stage to finish incomplete inserts or splits anymore. There was two
reasons for the cleanup step:

1. When a new tuple was inserted to a leaf page, the downlink in the parent
needed to be updated to contain (ie. to be consistent with) the new key.
Updating the parent in turn might require recursively updating the parent of
the parent. We now handle that by updating the parent while traversing down
the tree, so that when we insert the leaf tuple, all the parents are already
consistent with the new key, and the tree is consistent at every step.

2. When a page is split, we need to insert the downlink for the new right
page(s), and update the downlink for the original page to not include keys
that moved to the right page(s). We now handle that by setting a new flag,
F_FOLLOW_RIGHT, on the non-rightmost pages in the split. When that flag is
set, scans always follow the rightlink, regardless of the NSN mechanism used
to detect concurrent page splits. That way the tree is consistent right after
split, even though the downlink is still missing. This is very similar to the
way B-tree splits are handled. When the downlink is inserted in the parent,
the flag is cleared. To keep the insertion algorithm simple, when an
insertion sees an incomplete split, indicated by the F_FOLLOW_RIGHT flag, it
finishes the split before doing anything else.

These changes allow removing the whole "invalid tuple" mechanism, but I
retained the scan code to still follow invalid tuples correctly. While we
don't create any such tuples anymore, we want to handle them gracefully in
case you pg_upgrade a GiST index that has them. If we encounter any on an
insert, though, we just throw an error saying that you need to REINDEX.

The issue that got me into doing this is that if you did a checkpoint while
an insert or split was in progress, and the checkpoint finishes quickly so
that there is no WAL record related to the insert between RedoRecPtr and the
checkpoint record, recovery from that checkpoint would not know to finish
the incomplete insert. IOW, we have the same issue we solved with the
rm_safe_restartpoint mechanism during normal operation too. It's highly
unlikely to happen in practice, and this fix is far too large to backpatch,
so we're just going to live with in previous versions, but this refactoring
fixes it going forward.

With this patch, you don't get the annoying
'index "FOO" needs VACUUM or REINDEX to finish crash recovery' notices
anymore if you crash at an unfortunate moment.

off unless they guarantee that all writes to the BBU arrive in 8kB chunks.

Per discussion with Greg Smith

Noted by Thom Brown.

This function is like the PQserverVersion() function except
it returns the version of libpq, making it possible for a client
program or driver to determine which version of libpq is in
use at runtime, and not just at link time.

Suggested by Harald Armin Massa and several others.

Jaime Casanova

Add support for collecting "minidump" style crash dumps on
Windows, by setting up an exception handling filter. Crash
dumps will be generated in PGDATA/crashdumps if the directory
is created (the existance of the directory is used as on/off
switch for the generation of the dumps).

Craig Ringer and Magnus Hagander

Per report from Fujii Masao, and subsequent discussion.

One of the usages of the binary version is to read files in a different
encoding from the server encoding.

Dimitri Fontaine and Itagaki Takahiro.

documentation.  (Many were left over from the old pg_migrator naming.)

Noted by Tom Lane.

Fujii Masao.  Review by Alvaro Herrera, Tom Lane, and myself.

Fujii Masao

Recent versions of the Linux system header files cause xlogdefs.h to
believe that open_datasync should be the default sync method, whereas
formerly fdatasync was the default on Linux.  open_datasync is a bad
choice, first because it doesn't actually outperform fdatasync (in fact
the reverse), and second because we try to use O_DIRECT with it, causing
failures on certain filesystems (e.g., ext4 with data=journal option).
This part of the patch is largely per a proposal from Marti Raudsepp.
More extensive changes are likely to follow in HEAD, but this is as much
change as we want to back-patch.

Also clean up confusing code and incorrect documentation surrounding the
fsync_writethrough option.  Those changes shouldn't result in any actual
behavioral change, but I chose to back-patch them anyway to keep the
branches looking similar in this area.

In 9.0 and HEAD, also do some copy-editing on the WAL Reliability
documentation section.

Back-patch to all supported branches, since any of them might get used
on modern Linux versions.

First, avoid scanning the whole ProcArray once we know there
are at least commit_siblings active; second, skip the check
altogether if commit_siblings = 0.

Greg Smith

Teodor Sigaev, with some revision by Tom

This is a heavily revised version of builtin_knngist_core-0.9.  The
ordering operators are no longer mixed in with actual quals, which would
have confused not only humans but significant parts of the planner.
Instead, ordering operators are carried separately throughout planning and
execution.

Since the API for ambeginscan and amrescan functions had to be changed
anyway, this commit takes the opportunity to rationalize that a bit.
RelationGetIndexScan no longer forces a premature index_rescan call;
instead, callers of index_beginscan must call index_rescan too.  Aside from
making the AM-side initialization logic a bit less peculiar, this has the
advantage that we do not make a useless extra am_rescan call when there are
runtime key values.  AMs formerly could not assume that the key values
passed to amrescan were actually valid; now they can.

Teodor Sigaev and Tom Lane

Christoph Berg.

Per gripe from Andreas Scherbaum.

KaiGai Kohei, with a few changes by me.