The recent additions for FDW support required checking foreign-table-ness
in several places in the parse/plan chain.  While it's not clear whether
that would really result in a noticeable slowdown, it seems best to avoid
any performance risk by keeping a copy of the relation's relkind in
RangeTblEntry.  That might have some other uses later, anyway.
Per discussion.

Add functions plpy.quote_ident, plpy.quote_literal,
plpy.quote_nullable, which wrap the equivalent SQL functions.

To be able to propagate char * constness properly, make the argument
of quote_literal_cstr() const char *.  This also makes it more
consistent with quote_identifier().

Jan Urbański, reviewed by Hitoshi Harada, some refinements by Peter
Eisentraut

"SELECT ... INTO UNLOGGED tabname" works, but wasn't documented; CREATE
UNLOGGED SEQUENCE and CREATE UNLOGGED VIEW failed an assertion, instead
of throwing a sensible error.

Latter issue reported by Itagaki Takahiro; patch review by Tom Lane.

void_send is useful for the same reason that void_out doesn't throw error,
namely that someone might do "select void_returning_func(...)"  from a
client that prefers to operate in binary mode.  The void_recv function may
or may not have any practical use, but we provide it for symmetry.

Radosław Smogura

This was a leftover from the pre-8.1 design of junkfilters.  It doesn't
seem to have any reason to live, since it's merely a combination of two
easy function calls, and not a well-designed combination at that (it
encourages callers to leak the result tuple).

ExecUpdate checked for whether ExecBRUpdateTriggers had returned a new
tuple value by seeing if the returned tuple was pointer-equal to the old
one.  But the "old one" was in estate->es_junkFilter's result slot, which
would be scribbled on if we had done an EvalPlanQual update in response to
a concurrent update of the target tuple; therefore we were comparing a
dangling pointer to a live one.  Given the right set of circumstances we
could get a false match, resulting in not forcing the tuple to be stored in
the slot we thought it was stored in.  In the case reported by Maxim Boguk
in bug #5798, this led to "cannot extract system attribute from virtual
tuple" failures when trying to do "RETURNING ctid".  I believe there is a
very-low-probability chance of more serious errors, such as generating
incorrect index entries based on the original rather than the
trigger-modified version of the row.

In HEAD, change all of ExecBRInsertTriggers, ExecIRInsertTriggers,
ExecBRUpdateTriggers, and ExecIRUpdateTriggers so that they continue to
have similar APIs.  In the back branches I just changed
ExecBRUpdateTriggers, since there is no bug in the ExecBRInsertTriggers
case.

information schema documentation because it affects several tables.

File encodings can be specified separately from client encoding.
If not specified, client encoding is used for backward compatibility.

Cases when the encoding doesn't match client encoding are slower
than matched cases because we don't have conversion procs for other
encodings. Performance improvement would be be a future work.

Original patch by Hitoshi Harada, and modified by me.

Alexander Korotkov

This is both very useful in its own right, and an important test case
for the core FDW support.

This commit includes a small refactoring of copy.c to expose its option
checking code as a separately callable function.  The original patch
submission duplicated hundreds of lines of that code, which seemed pretty
unmaintainable.

Shigeru Hanada, reviewed by Itagaki Takahiro and Tom Lane

This commit provides the core code and documentation needed.  A contrib
module test case will follow shortly.

Shigeru Hanada, Jan Urbanski, Heikki Linnakangas

avg() because it was inaccurate.

Marko Kreen

from information_schema.referential_constraints might return several in
Postgres because we allow duplicate-named constraints in the same
schema.

type changes.

The invalidation will cause the type information to be refetched, and
everything will work.

Jan Urbański, reviewed by Alex Hunsaker

Add a new libpq connection option client_encoding (which includes the
existing PGCLIENTENCODING environment variable), which besides an
encoding name accepts a special value "auto" that tries to determine
the encoding from the locale in the client's environment, using the
mechanisms that have been in use in initdb.

psql sets this new connection option to "auto" when running from a
terminal and not overridden by setting PGCLIENTENCODING.

original code by Heikki Linnakangas, with subsequent contributions by
Jaime Casanova, Peter Eisentraut, Stephen Frost, Ibrar Ahmed

Add a fdwhandler column to pg_foreign_data_wrapper, plus HANDLER options
in the CREATE FOREIGN DATA WRAPPER and ALTER FOREIGN DATA WRAPPER commands,
plus pg_dump support for same.  Also invent a new pseudotype fdw_handler
with properties similar to language_handler.

This is split out of the "FDW API" patch for ease of review; it's all stuff
we will certainly need, regardless of any other details of the FDW API.
FDW handler functions will not actually get called yet.

In passing, fix some omissions and infelicities in foreigncmds.c.

Shigeru Hanada, Jan Urbanski, Heikki Linnakangas

configuration rules.

Erik Rijkers

This has been broken for awhile, but not clear it's worth back-patching.

Euler Taveira de Oliveira

The previous coding would try to process all SECTION_NONE items in the
initial sequential-restore pass, which failed if they were dependencies of
not-yet-restored items.  Fix by postponing such items into the parallel
processing pass once we have skipped any non-PRE_DATA item.

Back-patch into 9.0; the original parallel-restore coding in 8.4 did not
have this bug, so no need to change it.

Report and diagnosis by Arnd Hannemann.

intarray and tsearch2 both reference core support functions in their GIN
opclasses, and the signatures of those functions changed for 9.1.  We added
backwards-compatible pg_proc entries for the functions in order to allow
9.0 dump files to be restored at all, but that hack leaves the opclasses
pointing at pg_proc entries different from what they'd point to if the
contrib modules were installed fresh in 9.1.  To forestall any possibility
of future problems, fix the opclasses to match fresh installs via the
expedient of direct UPDATEs on pg_amproc in the update-from-unpackaged
scripts.  (Yech ... but the alternatives are worse, or require far more
effort than seems justified right now.)

Note: updating pg_amproc is sufficient because there will be no pg_depend
entries corresponding to these dependencies, since the referenced functions
are all pinned.

Per discussion after my commit o yesterday.

More useful state change for monitoring purposes, plus a
required change for synchronous replication patch.

Allow messages to be sent at different times, and greatly reduce
the frequency of hot standby feedback. Refactor to allow additional
message types.

Kevin Grittner

Applied a patch by Zoltán Böszörményi that makes ecpg's parser accept dynamic cursornames even in WHERE CURRENT OF clauses.

Shigeru HANADA

They share the same locking namespace with the existing session-level
advisory locks, but they are automatically released at the end of the
current transaction and cannot be released explicitly via unlock
functions.

Marko Tiikkaja, reviewed by me.

More generally, arrays are turned in Perl array references, and row and
composite types are turned into Perl hash references.  This is done
recursively, in a way that's natural to every Perl programmer.

To avoid a backwards compatibility hit, the string representation of
each structure is also available if the function requests it.

Authors: Alexey Klyukin and Alex Hunsaker.
Some code cleanups by me.

This allows the user to change the path to be used more easily.
Also, change URL in README.

ts_typanalyze.c computes MCE statistics as fractions of the non-null rows,
which seems fairly reasonable, and anyway changing it in released versions
wouldn't be a good idea.  But then ts_selfuncs.c has to account for that.
Failure to do so results in overestimates in columns with a significant
fraction of null documents.  Back-patch to 8.4 where this stuff was
introduced.

Jesper Krogh

Update script was being sloppy about two functions that have been changed
since 9.0.

Take care of a couple of discrepancies between what you get from a fresh
install and what the first-draft update-from-unpackaged scripts produced.