If a tuple was frozen while its predicate locks mattered,
read-write dependencies could be missed, resulting in failure to
detect conflicts which could lead to anomalies in committed
serializable transactions.

This field was added to the tag when we still thought that it was
necessary to carry locks forward to a new version of an updated
row.  That was later proven to be unnecessary, which allowed
simplification of the code, but elimination of xmin from the tag
was missed at the time.

Per report and analysis by Heikki Linnakangas.
Backpatch to 9.1.

Cédric Villemain and me.

Reviewed by Fabien COELHO.

Clamp the minimum sleep time during immediate shutdown or crash to a
minimum of zero, not a maximum of one second.  The previous code could
result in a negative sleep time, leading to failure in select() calls.

Also, on crash recovery, reset AbortStartTime as soon as SIGKILL is sent
or abort processing has commenced instead of waiting until the startup
process completes.  Reset AbortStartTime as soon as SIGKILL is sent,
too, to avoid doing that repeatedly.

Per trouble report from Jeff Janes on
CAMkU=1xd3=wFqZwwuXPWe4BQs3h1seYo8LV9JtSjW5RodoPxMg@mail.gmail.com

Author: MauMau

Isolate transaction latency (elapsed time between submitting first
command and receiving response to last command) from client-side delays
pertaining to the --rate schedule.  Under --rate, report schedule lag as
defined in the documentation.  Report latency standard deviation
whenever we collect the measurements to do so.  All of these changes
affect --progress messages and the final report.

Fabien COELHO, reviewed by Pavel Stehule.

Oversight in commit 4a87f308.

Fabien COELHO

Mention that link mode uses less disk space, and uses junction points on
Windows.

Backpatch to 9.3.

Also, make sure they pass on all transaction isolation levels.

Previously, isolationtester would forbid returning tuples in
session-specific teardown (but not global teardown), as well as in
global setup.  Allow these places to return tuples, too.

Issue error for SET LOCAL/CONSTRAINTS/TRANSACTION outside a transaction
block, as they have no effect.

Per suggestion from Morten Hustveit

Maciek Sakrejda

Report from Kevin Hale Boyes.

DISCARD ALL will now discard cached sequence information, as well.

Fabrízio de Royes Mello, reviewed by Zoltán Böszörményi, with some
further tweaks by me.

Gilles Darold, reviewed by Pavel Stehule

It makes for cleaner code to have separate Get/Add functions for PostingItems
and ItemPointers.  A few callsites that have to deal with both types need to
be duplicated because of this, but all the callers have to know which one
they're dealing with anyway. Overall, this reduces the amount of casting
required.

Extracted from Alexander Korotkov's larger patch to change the data page
format.

The cancel handler was uselessly set up even before the first connection
was opened.  By setting it up afterwards, the user can use Ctrl+C to
abort psql if the initial connection attempt hangs.
Reviewed-by: Dean Rasheed <dean.a.rasheed@gmail.com>
Reviewed-by: Ryan Kelly <rpkelly22@gmail.com>

This is in support of a future REINDEX CONCURRENTLY feature.

Michael Paquier

With the PGXS boilerplate in place, pg_xlogdump currently fails with an
ominous error message that certain targets cannot be built because
certain files do not exist.  Remove that and instead throw a quick error
message alerting the user of the actual problem, which should be easier
to diagnose that the statu quo.

Andres Freund

Error noted by Andres Freund.

Push dependency on installdirs down to individual targets.

Christoph Berg

Previously bms_add_member() would palloc a whole-new copy of the existing
set, copy the words, and pfree the old one. repalloc() is potentially much
faster, and more importantly, this is less surprising if CurrentMemoryContext
is not the same as the context the old set is in. bms_add_member() still
allocates a new bitmapset in CurrentMemoryContext if NULL is passed as
argument, but that is a lot less likely to induce bugs.

Nicholas White.

lo_open registers the currently active snapshot, and checks if the
large object exists after that. Normally, snapshots registered by lo_open
are unregistered at end of transaction when the lo descriptor is closed, but
if we error out before the lo descriptor is added to the list of open
descriptors, it is leaked. Fix by moving the snapshot registration to after
checking if the large object exists.

Reported by Pavel Stehule. Backpatch to 8.4. The snapshot registration
system was introduced in 8.4, so prior versions are not affected (and not
supported, anyway).

Pavan Deolasee

This should have been done when the json functionality was added to
hstore in 9.3.0. To handle this correctly, the upgrade script therefore
uses conditional logic by using plpgsql in a DO statement to add the two
new functions and the new cast. If hstore_to_json_loose is detected as
already present and dependent on the hstore extension nothing is done.
This will require that the database be loaded with plpgsql.

People who have installed the earlier and spurious 1.1 version of hstore
will need to do:

	ALTER EXTENSION hstore UPDATE;

to pick up the new functions properly.

Cédric Villemain

David Rowley, after a suggestion from Heikki Linnakangas.  Reviewed by
Albe Laurenz, and further edited by me.

The behaviour in json_populate_record() and json_populate_recordset()
was changed during development but the docs were not.

There is a rare race condition, when a transaction that inserted a tuple
aborts while vacuum is processing the page containing the inserted tuple.
Vacuum prunes the page first, which normally removes any dead tuples, but
if the inserting transaction aborts right after that, the loop after
pruning will see a dead tuple and remove it instead. That's OK, but if the
page is on a table with no indexes, and the page becomes completely empty
after removing the dead tuple (or tuples) on it, it will be immediately
marked as all-visible. That's OK, but the sanity check in vacuum would
throw a warning because it thinks that the page contains dead tuples and
was nevertheless marked as all-visible, even though it just vacuumed away
the dead tuples and so it doesn't actually contain any.

Spotted this while reading the code. It's difficult to hit the race
condition otherwise, but can be done by putting a breakpoint after the
heap_page_prune() call.

Backpatch all the way to 8.4, where this code first appeared.

Previous code gave a mean delay 0.44% below target.  This change also
has the effect of increasing the maximum possible delay.

Fabien COELHO

B-tree operators are not allowed to leak memory into the current memory
context. Range_cmp leaked detoasted copies of the arguments. That caused
a quick out-of-memory error when creating an index on a range column.

Reported by Marian Krucina, bug #8468.

Though @libdir@ almost always matches @abs_builddir@ in this context,
the test could only fail if they differed.  Back-patch to 9.1, where the
test was introduced.

Hamid Quddus Akhtar

Fabien COELHO

Mike Blackwell and Robert Haas