Avoid copying index tuples when building an index.

The previous code, perhaps out of concern for avoid memory leaks, formed
the tuple in one memory context and then copied it to another memory
context.  However, this doesn't appear to be necessary, since
index_form_tuple and the functions it calls take precautions against
leaking memory.  In my testing, building the tuple directly inside the
sort context shaves several percent off the index build time.
Rearrange things so we do that.

Patch by me.  Review by Amit Kapila, Tom Lane, Andres Freund.
Fix inadequately-sized output buffer in contrib/unaccent.

The output buffer size in unaccent_lexize() was calculated as input string
length times pg_database_encoding_max_length(), which effectively assumes
that replacement strings aren't more than one character.  While that was
all that we previously documented it to support, the code actually has
always allowed replacement strings of arbitrary length; so if you tried
to make use of longer strings, you were at risk of buffer overrun.  To fix,
use an expansible StringInfo buffer instead of trying to determine the
maximum space needed a-priori.

This would be a security issue if unaccent rules files could be installed
by unprivileged users; but fortunately they can't, so in the back branches
the problem can be labeled as improper configuration by a superuser.
Nonetheless, a memory stomp isn't a nice way of reacting to improper
configuration, so let's back-patch the fix.
Improve handling of OOM score adjustment in sample Linux start script.

Per a suggestion from Christoph Berg.
Remove some useless code in the configure script.

Almost ten years ago, commit e48322a6d6cfce1ec52ab303441df329ddbc04d1 broke
the logic in ACX_PTHREAD by looping through all the possible flags rather
than stopping with the first one that would work.  This meant that
$acx_pthread_ok was no longer meaningful after the loop; it would usually
be "no", whether or not we'd found working thread flags.  The reason nobody
noticed is that Postgres doesn't actually use any of the symbols set up
by the code after the loop.  Rather than complicate things some more to
make it work as designed, let's just remove all that dead code, and thereby
save a few cycles in each configure run.
Refactor CREATE/ALTER DATABASE syntax so options need not be keywords.

Most of the existing option names are keywords anyway, but we can get rid
of LC_COLLATE and LC_CTYPE as keywords known to the lexer/grammar.  This
immediately reduces the size of the grammar tables by about 8KB, and will
save more when we add additional CREATE/ALTER DATABASE options in future.

A side effect of the implementation is that the CONNECTION LIMIT option
can now also be spelled CONNECTION_LIMIT.  We choose not to document this,
however.

Vik Fearing, based on a suggestion by me; reviewed by Pavel Stehule
Allow CREATE/ALTER DATABASE to manipulate datistemplate and datallowconn.

Historically these database properties could be manipulated only by
manually updating pg_database, which is error-prone and only possible for
superusers.  But there seems no good reason not to allow database owners to
set them for their databases, so invent CREATE/ALTER DATABASE options to do
that.  Adjust a couple of places that were doing it the hard way to use the
commands instead.

Vik Fearing, reviewed by Pavel Stehule
Prevent psql from issuing BEGIN before ALTER SYSTEM when AUTOCOMMIT is off.

The autocommit-off mode works by issuing an implicit BEGIN just before
any command that is not already in a transaction block and is not itself
a BEGIN or other transaction-control command, nor a command that
cannot be executed inside a transaction block. This commit prevents psql
from issuing such an implicit BEGIN before ALTER SYSTEM because it's
not allowed inside a transaction block.

Backpatch to 9.4 where ALTER SYSTEM was added.

Report by Feike Steenbergen
Add some errdetail to checkRuleResultList().

This function wasn't originally thought to be really user-facing,
because converting a table to a view isn't something we expect people
to do manually.  So not all that much effort was spent on the error
messages; in particular, while the code will complain that you got
the column types wrong it won't say exactly what they are.  But since
we repurposed the code to also check compatibility of rule RETURNING
lists, it's definitely user-facing.  It now seems worthwhile to add
errdetail messages showing exactly what the conflict is when there's
a mismatch of column names or types.  This is prompted by bug #10836
from Matthias Raffelsieper, which might have been forestalled if the
error message had reported the wrong column type as being "record".

Back-patch to 9.4, but not into older branches where the set of
translatable error strings is supposed to be stable.
pg_upgrade:  no need to remove "members" files for pre-9.3 upgrades

Per analysis by Alvaro

Backpatch through 9.3
Rename logical decoding's pg_llog directory to pg_logical.

The old name wasn't very descriptive as of actual contents of the
directory, which are historical snapshots in the snapshots/
subdirectory and mappingdata for rewritten tuples in
mappings/. There's been a fair amount of discussion what would be a
good name. I'm settling for pg_logical because it's likely that
further data around logical decoding and replication will need saving
in the future.

Also add the missing entry for the directory into storage.sgml's list
of PGDATA contents.

Bumps catversion as the data directories won't be compatible.
pg_upgrade:  preserve database and relation minmxid values

Also set these values for pre-9.3 old clusters that don't have values to
preserve.

Analysis by Alvaro

Backpatch through 9.3
Smooth reporting of commit/rollback statistics.

If a connection committed or rolled back any transactions within a
PGSTAT_STAT_INTERVAL pacing interval without accessing any tables,
the reporting of those statistics would be held up until the
connection closed or until it ended a PGSTAT_STAT_INTERVAL interval
in which it had accessed a table.  This could result in under-
reporting of transactions for an extended period, followed by a
spike in reported transactions.

While this is arguably a bug, the impact is minimal, primarily
affecting, and being affected by, monitoring software.  It might
cause more confusion than benefit to change the existing behavior
in released stable branches, so apply only to master and the 9.4
beta.

Gurjeet Singh, with review and editing by Kevin Grittner,
incorporating suggested changes from Abhijit Menon-Sen and Tom
Lane.
Support vpath builds in TAP tests
Use a separate temporary directory for the Unix-domain socket

Creating the Unix-domain socket in the build directory can run into
name-length limitations.  Therefore, create the socket file in the
default temporary directory of the operating system.  Keep the temporary
data directory etc. in the build tree.
Improve support for composite types in PL/Python.

Allow PL/Python functions to return arrays of composite types.
Also, fix the restriction that plpy.prepare/plpy.execute couldn't
handle query parameters or result columns of composite types.

In passing, adopt a saner arrangement for where to release the
tupledesc reference counts acquired via lookup_rowtype_tupdesc.
The callers of PLyObject_ToCompositeDatum were doing the lookups,
but then the releases happened somewhere down inside subroutines
of PLyObject_ToCompositeDatum, which is bizarre and bug-prone.
Instead release in the same function that acquires the refcount.

Ed Behn and Ronan Dunklau, reviewed by Abhijit Menon-Sen
Redesign API presented by nodeAgg.c for ordered-set and similar aggregates.

The previous design exposed the input and output ExprContexts of the
Agg plan node, but work on grouping sets has suggested that we'll regret
doing that.  Instead provide more narrowly-defined APIs that can be
implemented in multiple ways, namely a way to get a short-term memory
context and a way to register an aggregate shutdown callback.

Back-patch to 9.4 where the bad APIs were introduced, since we don't
want third-party code using these APIs and then having to change in 9.5.

Andrew Gierth
Don't cache per-group context across the whole query in orderedsetaggs.c.

Although nodeAgg.c currently uses the same per-group memory context for
all groups of a query, that might change in future.  Avoid assuming it.
This costs us an extra AggCheckCallContext() call per group, but that's
pretty cheap and is probably good from a safety standpoint anyway.

Back-patch to 9.4 in case any third-party code copies this logic.

Andrew Gierth
Split out the description of page-level lock as new subsection in document.

Michael Banck
Refactor pg_receivexlog main loop code, for readability.

Previously the source codes for receiving the data and for
polling the socket were included in pg_receivexlog main loop.
This commit splits out them as separate functions. This is
useful for improving the readability of main loop code and
making the future pg_receivexlog-related patch simpler.
Fix double-free bug of WAL streaming buffer in pg_receivexlog.

This bug was introduced while refactoring in commit 74cbe96.