Missed in commit 62e66640.

This reverts the code changes in 50c13748,
which turned out to induce crashes and not completely fix the problem
anyway.  That commit only considered single subqueries that were excluded
by constraint-exclusion logic, but actually the problem also exists for
subqueries that are appendrel members (ie part of a UNION ALL list).  In
such cases we can't add a dummy subpath to the appendrel's AppendPath list
without defeating the logic that recognizes when an appendrel is completely
excluded.  Instead, fix the problem by having setrefs.c scan the rangetable
an extra time looking for subqueries that didn't get into the plan tree.
(This approach depends on the 9.2 change that made set_subquery_pathlist
generate dummy paths for excluded single subqueries, so that the exclusion
behavior is the same for single subqueries and appendrel members.)

Note: it turns out that the appendrel form of the missed-permissions-checks
bug exists as far back as 8.4.  However, since the practical effect of that
bug seems pretty minimal, consensus is to not attempt to fix it in the back
branches, at least not yet.  Possibly we could back-port this patch once
it's gotten a reasonable amount of testing in HEAD.  For the moment I'm
just going to revert the previous patch in 9.2.

If a standby server has a cascading standby server connected to it, it's
possible that WAL has already been sent up to the next WAL page boundary,
splitting a WAL record in the middle, when the first standby server is
promoted. Don't throw an assertion failure or error in walsender if that
happens.

Also, fix a variant of the same bug in pg_receivexlog: if it had already
received WAL on previous timeline up to a segment boundary, when the
upstream standby server is promoted so that the timeline switch record falls
on the previous segment, pg_receivexlog would miss the segment containing
the timeline switch. To fix that, have walsender send the position of the
timeline switch at end-of-streaming, in addition to the next timeline's ID.
It was previously assumed that the switch happened exactly where the
streaming stopped.

Note: this is an incompatible change in the streaming protocol. You might
get an error if you try to stream over timeline switches, if the client is
running 9.3beta1 and the server is more recent. It should be fine after a
reconnect, however.

Reported by Fujii Masao.

What we have implemented is a radix tree (or a radix trie or a patricia
trie), but the docs and code comments incorrectly called it a "suffix tree".

Alexander Korotkov

Previously this state was represented by whether the view's disk file had
zero or nonzero size, which is problematic for numerous reasons, since it's
breaking a fundamental assumption about heap storage.  This was done to
allow unlogged matviews to revert to unpopulated status after a crash
despite our lack of any ability to update catalog entries post-crash.
However, this poses enough risk of future problems that it seems better to
not support unlogged matviews until we can find another way.  Accordingly,
revert that choice as well as a number of existing kluges forced by it
in favor of creating a pg_class.relispopulated flag column.

Very old versions of msgfmt choke on these specific messages, for reasons
that are unclear at the moment.  Remove them so that we can ship a beta
release and not get complaints from testers (these messages will just go
untranslated, instead, and we're hardly at 100% coverage anyway).
Peter Eisentraut will look for a better fix later.

The initial implementation of this feature was really unsupportable,
because it's relying on the physical size of an on-disk file to carry the
relation's populated/unpopulated state, which is at least a modularity
violation and could have serious long-term consequences.  We could say that
an unlogged matview goes to empty on crash, but not everybody likes that
definition, so let's just remove the feature for 9.3.  We can add it back
when we have a less klugy implementation.

I left the grammar and tab-completion support for CREATE UNLOGGED
MATERIALIZED VIEW in place, since it's harmless and allows delivering a
more specific error message about the unsupported feature.

I'm committing this separately to ease identification of what should be
reverted when/if we are able to re-enable the feature.

Previous coding set the SQL buffer but never executed

Bug noted by me during beta testing

Removal of doc adjustment and release note mention as well.

Print the command tag if we get PGRES_COMMAND_OK, and throw an error for
other cases.  Per gripe from Michael Paquier.

In passing, add an fflush(), just to be real sure the output appears
before we sleep.

Per report from Fujii Masao, with regression test using his example.

Bug reported on IRC - fix due to Andrew Gierth.

A view defined as "select <something> where false" had the curious property
that the system wouldn't check whether users had the privileges necessary
to select from it.  More generally, permissions checks could be skipped
for tables referenced in sub-selects or views that were proven empty by
constraint exclusion (although some quick testing suggests this seldom
happens in cases of practical interest).  This happened because the planner
failed to include rangetable entries for such tables in the finished plan.

This was noticed in connection with erroneous handling of materialized
views, but actually the issue is quite unrelated to matviews.  Therefore,
revert commit 200ba166 in favor of a more
direct test for the real problem.

Back-patch to 9.2 where the bug was introduced (by commit
7741dd65).

Test case by Andres Freund for bug fixed by Tom Lane's refactoring
in commit 5194024d

The value is not used anywhere in code, but will
allow future changes to the checksum version
should that become necessary in the future.

logs the heap page and sets the LSN. Otherwise a
checkpoint could occur between those actions and
leave us in an inconsistent state.

Jeff Davis

Ants Aasma and Jeff Davis

This reverts commit 87306184.  The
behavior in certain cases is still being debated, and it's too late to
solve this before beta.

This patch gets rid of the concept of, and infrastructure for,
non-canonical PathKeys; we now only ever create canonical pathkey lists.

The need for non-canonical pathkeys came from the desire to have
grouping_planner initialize query_pathkeys and related pathkey lists before
calling query_planner.  However, since query_planner didn't actually *do*
anything with those lists before they'd been made canonical, we can get rid
of the whole mess by just not creating the lists at all until the point
where we formerly canonicalized them.

There are several ways in which we could implement that without making
query_planner itself deal with grouping/sorting features (which are
supposed to be the province of grouping_planner).  I chose to add a
callback function to query_planner's API; other alternatives would have
required adding more fields to PlannerInfo, which while not bad in itself
would create an ABI break for planner-related plugins in the 9.2 release
series.  This still breaks ABI for anything that calls query_planner
directly, but it seems somewhat unlikely that there are any such plugins.

I had originally conceived of this change as merely a step on the way to
fixing bug #8049 from Teun Hoogendoorn; but it turns out that this fixes
that bug all by itself, as per the added regression test.  The reason is
that now get_eclass_for_sort_expr is adding the ORDER BY expression at the
end of EquivalenceClass creation not the start, and so anything that is in
a multi-member EquivalenceClass has already been created with correct
em_nullable_relids.  I am suspicious that there are related scenarios in
which we still need to teach get_eclass_for_sort_expr to compute correct
nullable_relids, but am not eager to risk destabilizing either 9.2 or 9.3
to fix bugs that are only hypothetical.  So for the moment, do this and
stop here.

Back-patch to 9.2 but not to earlier branches, since they don't exhibit
this bug for lack of join-clause-movement logic that depends on
em_nullable_relids being correct.  (We might have to revisit that choice
if any related bugs turn up.)  In 9.2, don't change the signature of
make_pathkeys_for_sortclauses nor remove canonicalize_pathkeys, so as
not to risk more plugin breakage than we have to.

Patch b19e4250 attempted to
preserve existing behavior regarding statistics generation in the
case that a truncation attempt was canceled due to lock conflicts.
It failed to do this accurately in two regards: (1) autovacuum had
previously generated statistics if the truncate attempt failed to
initially get the lock rather than having started the attempt, and
(2) the VACUUM ANALYZE command had always generated statistics.

Both of these changes were unintended, and are reverted by this
patch.  On review, there seems to be consensus that the previous
failure to generate statistics when the truncate was terminated
was more an unfortunate consequence of how that effort was
previously terminated than a feature we want to keep; so this
patch generates statistics even when an autovacuum truncation
attempt terminates early.  Another unintended change which is kept
on the basis that it is an improvement is that when a VACUUM
command is truncating, it will the new heuristic for avoiding
blocking other processes, rather than keeping an
AccessExclusiveLock on the table for however long the truncation
takes.

Per multiple reports, with some renaming per patch by Jeff Janes.

Backpatch to 9.0, where problem was created.

Previously, libpq and the backend had opposite ideas about whether
it was necessary for the client to send a CopyDone message after
receiving an ErrorResponse, making it impossible to cleanly exit
COPY BOTH mode.  Fix libpq so that works correctly, adopting the
backend's notion that an ErrorResponse kills the copy in both
directions.

Adjust receivelog.c to avoid a degradation in the quality of the
resulting error messages.  libpqwalreceiver.c is already doing
the right thing, so no adjustment needed there.

Add an explicit statement to the documentation explaining how
this part of the protocol is supposed to work, in the hopes of
avoiding future confusion in this area.

Since the consequences of all this confusion are very limited,
especially in the back-branches where no client ever attempts
to exit COPY BOTH mode without closing the connection entirely,
no back-patch.

Isolate checksum calculation to its own module, so that bufpage
knows little if anything about the details of the calculation.

This implementation is a modified FNV-1a hash checksum, details
of which are given in the new checksum.c header comments.

Basic implementation only, so we fix the output value.

Later related commits will add version numbers to pg_control,
compiler optimization flags and memory barriers.

Ants Aasma, reviewed by Jeff Davis and Simon Riggs

Choose a saner ordering of parameters (adding a new input param after
the output params seemed a bit random), update the function's header
comment to match reality (cmon folks, is this really that hard?),
get rid of useless and sloppily-defined distinction between
PROCESS_UTILITY_SUBCOMMAND and PROCESS_UTILITY_GENERATED.

We mustn't run any of the event-trigger support code when handling
utility statements like START TRANSACTION or ABORT, because that code
may need to refresh event-trigger cache data, which requires being
inside a valid transaction.  (This mistake explains the consistent
build failures exhibited by the CLOBBER_CACHE_ALWAYS buildfarm members,
as well as some irreproducible failures on other members.)

The least messy fix seems to be to break standard_ProcessUtility into two
functions, one that handles all the statements not supported by event
triggers, and one that contains the event-trigger support code and handles
the statements that are supported by event triggers.

This change also fixes several inconsistencies, such as four cases where
support had been installed for "ddl_event_start" but not "ddl_event_end"
triggers, plus the fact that InvokeDDLCommandEventTriggersIfSupported()
paid no mind to isCompleteQuery.

Dimitri Fontaine and Tom Lane

Move checking for unscannable matviews into ExecOpenScanRelation, which is
a better place for it first because the open relation is already available
(saving a relcache lookup cycle), and second because this eliminates the
problem of telling the difference between rangetable entries that will or
will not be scanned by the query.  In particular we can get rid of the
not-terribly-well-thought-out-or-implemented isResultRel field that the
initial matviews patch added to RangeTblEntry.

Also get rid of entirely unnecessary scannability check in the rewriter,
and a bogus decision about whether RefreshMatViewStmt requires a parse-time
snapshot.

catversion bump due to removal of a RangeTblEntry field, which changes
stored rules.

The old phrasing appeared to imply that the failure was terminal.
Improve that by indicating that archiving will be tried again later.

ORDER BY expressions were being treated the same as regular aggregate
arguments for purposes of collation determination, but really they should
not affect the aggregate's collation at all; only collations of the
aggregate's regular arguments should affect it.

In many cases this mistake would lead to incorrectly throwing a "collation
conflict" error; but in some cases the corrected code will silently assign
a different collation to the aggregate than before, for example
	agg(foo ORDER BY bar COLLATE "x")
which will now use foo's collation rather than "x" for the aggregate.
Given this risk and the lack of field complaints about the issue, it
doesn't seem prudent to back-patch.

In passing, rearrange code in assign_collations_walker so that we don't
need multiple copies of the standard logic for computing collation of a
node with children.  (Previously, CaseExpr duplicated the standard logic,
and we would have needed a third copy for Aggref without this change.)

Andrew Gierth and David Fetter

Ensure that user created rows in extension tables get dumped if the table is explicitly requested, either with a -t/--table switch of the table itself, or by -n/--schema switch of the schema containing the extension table. Patch reviewed by Vibhor Kumar and Dimitri Fontaine.

Backpatched to 9.1 when the extension management facility was added.

There's probably no real bug here at present, so not backpatching.
But it seems good to make these bits consistent with the rest of
libpq, so as to avoid future surprises.

Patch by me.  Review by Tom Lane.

There was a high probability of two or more concurrent C.I.C. commands
deadlocking just before completion, because each would wait for the others
to release their reference snapshots.  Fix by releasing the snapshot
before waiting for other snapshots to go away.

Per report from Paul Hinze.  Back-patch to all active branches.

Peter Geoghegan

On non-Windows systems, sys/time.h was pulled in by portability/instr_time.h,
which pulled in time.h. We certainly should include time.h directly, since
we're using time(2), but the indirect include masked the problem on most
platforms.

Andres Freund

This was due to incomplete implementation of rowcount reporting
for RMV, which was due to initial waffling on whether it should
be provided.  It seems unlikely to be a useful or universally
available  number as more sophisticated techniques for maintaining
matviews are added, so remove the partial support rather than
completing it.

Per report of Jeevan Chalke, but with a different fix

Continue to allow a request for synchronous
checkpoints as a mechanism in case of problems.