After the planner was fixed to convert some IN/EXISTS subqueries into
semijoins or antijoins, we had to prevent it from doing that in some
cases where the plans risked getting much worse.  The reason the plans
got worse was that in the unoptimized implementation, subqueries could
reference parameters from the outer query at any join level, and so
full table scans could be avoided even if they were one or more levels
of join below where the semi/anti join would be.  Now that we have
sufficient mechanism in the planner to handle such cases properly,
it should no longer be necessary to play dumb here.

This reverts commits 07b9936a and
cd1f0d04.  The latter was a stopgap
fix that wasn't really sufficiently analyzed at the time.  Rather
than just restricting ourselves to cases where the new join can be
stacked on the right-hand input, we should also consider whether it
can be stacked on the left-hand input.

This patch fixes the planner so that it can generate nestloop-with-
inner-indexscan plans even with one or more levels of joining between
the indexscan and the nestloop join that is supplying the parameter.
The executor was fixed to handle such cases some time ago, but the
planner was not ready.  This should improve our plans in many situations
where join ordering restrictions formerly forced complete table scans.

There is probably a fair amount of tuning work yet to be done, because
of various heuristics that have been added to limit the number of
parameterized paths considered.  However, we are not going to find out
what needs to be adjusted until the code gets some real-world use, so
it's time to get it in there where it can be tested easily.

Note API change for index AM amcostestimate functions.  I'm not aware of
any non-core index AMs, but if there are any, they will need minor
adjustments.

Hitherto, the information schema only showed explicitly granted
privileges that were visible in the *acl catalog columns.  If no
privileges had been granted, the implicit privileges were not shown.

To fix that, add an SQL-accessible version of the acldefault()
function, and use that inside the aclexplode() calls to substitute the
catalog-specific default privilege set for null values.

reviewed by Abhijit Menon-Sen

In e5e2fc84, blank lines were removed
after a comment block, which now looks as though the comment refers to
the immediately following code, but it actually refers to the
preceding code.  So put the blank lines back.

This has been the behavior already in most cases, but through
omission, ALTER DOMAIN / OWNER TO and ALTER DOMAIN / SET SCHEMA would
silently work on non-domain types as well.

Those fields only appear in the structs so that genbki.pl can create
the BKI bootstrap files for the catalogs.  But they are not actually
usable from C.  So hiding them can prevent coding mistakes, saves
stack space, and can help the compiler.

In certain catalogs, the first variable-length field has been kept
visible after manual inspection.  These exceptions are noted in C
comments.

reviewed by Tom Lane

Normally, accessing variable-length members of catalog structures past
the first one doesn't work at all.  Here, it happened to work because
indnatts was checked to be 1, and so the defined FormData_pg_index
layout, using int2vector[1] and oidvector[1] for variable-length
arrays, happened to match the actual memory layout.  But it's a very
fragile assumption, and it's not in a performance-critical path, so
code it properly using heap_getattr() instead.

bug analysis by Tom Lane

Noted by Josh Kupershmidt.

Per a suggestion from Sergey Konoplev

Peter Geoghegan

Parallel dump will need to repeat these steps for each new connection,
so it's better to have this logic in its own function.

Extracted (with some changes) from a much larger patch
by Joachim Wieland.

Dean Rasheed

Our own qsort_arg() implementation doesn't have the defect previously
observed to affect only QNX 4, so it seems sufficiently to assert that
it isn't broken rather than retesting.  Also, update a few comments to
clarify why it's valuable to retain a tie-break rule based on CTID
during index builds.

Peter Geoghegan, with slight tweaks by me.

We now use the same error message for ALTER TABLE .. ADD COLUMN or
ALTER TABLE .. RENAME COLUMN that we do for CREATE TABLE.  The old
message was accurate, but might be confusing to users not aware of our
system columns.

Vik Reykja, with some changes by me, and further proofreading by Tom Lane

To make it wake up promptly when activity starts again, backends nudge it
by setting a latch in MarkBufferDirty(). The latch is kept set while
bgwriter is active, so there is very little overhead from that when the
system is busy. It is only armed before going into longer sleep.

Peter Geoghegan, with some changes by me.

Adds a counter that tracks number of deadlocks that occurred in
each database to pg_stat_database.

Magnus Hagander, reviewed by Jaime Casanova

This doesn't do anything useful just yet, but is intended as supporting
infrastructure for allowing sepgsql to sensibly check DROP permissions.

KaiGai Kohei and Robert Haas

Add counters for number and size of temporary files used
for spill-to-disk queries for each database to the
pg_stat_database view.

Tomas Vondra, review by Magnus Hagander

Rip out a regression test that doesn't play well with settings put in
place by the build farm, and rewrite the code in CheckIndexCompatible
in a hopefully more transparent style.

Patch by me; review by Tom Lane, Jeff Davis, and Peter Geoghegan.

This enables a bunch of features, notably ON_ERROR_ROLLBACK.  It also
makes COPY failure (either in the server or psql) as a whole behave more
sanely in psql.

Additionally, having more commands in the same command line as COPY
works better (though since psql splits lines at semicolons, this doesn't
matter much unless you're using -c).

Also tighten a couple of switches on PQresultStatus() to add
PGRES_COPY_BOTH support and stop assuming that unknown statuses received
are errors; have those print diagnostics where warranted.

Author: Noah Misch

This gives up the "don't rewrite the index" behavior in a couple of
relatively unimportant cases, such as changing between an array type
and an unconstrained domain over that array type, in return for
making this code more future-proof.

Noah Misch

Base backup follows recommended procedure, plus goes to great
lengths to ensure that partial page writes are avoided.

Jun Ishizuka and Fujii Masao, with minor modifications

This reports the depth level of triggers currently in execution, or zero
if not called from inside a trigger.

No catversion bump in this patch, but you have to initdb if you want
access to the new function.

Author: Kevin Grittner

have pg_upgrade allocate a maximum fixed size buffer for testing the
library file name, rather than base the allocation on the library name.

Backpatch to 9.1.

"plpython2" when upgrading from pre-PG 9.1.  Patch to head and 9.1.

Per report from Peter.

check cluster version numbers, and fix missing table alias.

Replication occurs only to memory on standby, not to disk,
so provides additional performance if user wishes to
reduce durability level slightly. Adds concept of multiple
independent sync rep queues.

Fujii Masao and Simon Riggs

format_type_be() takes care of any needed quoting itself.

to match surrounding outdenting.

Drop the role we create, so regression tests pass even when run more
than once against the same cluster, a problem noted by Tom Lane and
Jeff Janes.  Also, rename the temporary role so that it starts with
"regress_", to make it unlikely that we'll collide with an existing
role name while running "make installcheck", per further gripe from
Tom Lane.