(I'm not entirely sure that we've finished bikeshedding the syntax details,
but the functionality seems OK.)

Pavel Stehule, reviewed by Stephen Frost and Tom Lane

Fujii Masao, reviewed by Robert Haas, Stephen Frost, and Magnus Hagander.

They are expected to be used by extension modules like file_fdw.
There are no user-visible changes.

Itagaki Takahiro
Reviewed and tested by Kevin Grittner and Noah Misch.

output.

Normally, pg_dump summarily excludes functions in pg_catalog from
consideration.  However, some extensions may create functions in pg_catalog
(adminpack already does that, and extensions for procedural languages will
likely do it too).  In binary-upgrade mode, we have to dump such functions,
or the extension will be incomplete after upgrading.  Per experimentation
with adminpack.

Recent releases had a check on rel->rd_refcnt in heap_drop_with_catalog,
but failed to cover the possibility of pending trigger events at DROP time.
(Before 8.4 we didn't even check the refcnt.)  When the trigger events were
eventually fired, you'd get "could not open relation with OID nnn" errors,
as in recent report from strk.  Better to throw a suitable error when the
DROP is attempted.

Also add a similar check in DROP INDEX.

Back-patch to all supported branches.

All the other ones that are primarily a new datatype say "data type for
<purpose>", so make this one similar.

Comment about MaxAllocSize was not updated when the TOAST-header macros
were replaced in 8.3 "varvarlena" changes.  Per report from Frederik Ramm.

Per reports from Fujii Masao.

The new name, max_pred_locks_per_transaction, is shorter.

Kevin Grittner, per discussion.

Also add make check-world target, and refactor pg_regress invocation
code in makefiles a bit.

When the new type is an unconstrained domain over the old type, we don't
need to rewrite the table.

Noah Misch and Robert Haas

Initially it was called int_aggregate after the old SQL file, but since
the documentation just says "intagg" and that's also the directory name,
let's conform to that instead.

Noted by Bernd Helmle

though must not update the last transaction timestamp.
Plus comment and message cleanup for recent named restore point.

Fujii Masao, minor changes by me

Untested, but we'll soon see if the buildfarm likes this.

The original design of pg_available_extensions did not consider the
possibility of version-specific control files.  Split it into two views:
pg_available_extensions shows information that is generic about an
extension, while pg_available_extension_versions shows all available
versions together with information that could be version-dependent.
Also, add an SRF pg_extension_update_paths() to assist in checking that
a collection of update scripts provide sane update path sequences.

Bug report and fix by Andres Freund

From first pass of testing.  Notably, there seems to be no need for
adminpack--unpackaged--1.0.sql because none of the objects that the
old module creates would ever be dumped by pg_dump anyway (they are
all in pg_catalog).

It was never terribly consistent to use OR REPLACE (because of the lack of
comparable functionality for data types, operators, etc), and
experimentation shows that it's now positively pernicious in the extension
world.  We really want a failure to occur if there are any conflicts, else
it's unclear what the extension-ownership state of the conflicted object
ought to be.  Most of the time, CREATE EXTENSION will fail anyway because
of conflicts on other object types, but an extension defining only
functions can succeed, with bad results.

This isn't fully tested as yet, in particular I'm not sure that the
"foo--unpackaged--1.0.sql" scripts are OK.  But it's time to get some
buildfarm cycles on it.

sepgsql is not converted to an extension, mainly because it seems to
require a very nonstandard installation process.

Dimitri Fontaine and Tom Lane

This avoids the need to find a way to make PGXS' .sql.in-to-.sql rule
insert the right thing.  We'll just deprecate use of that hack for
extensions.

This allows us to have an unambiguous rule for deconstructing the names
of script files and secondary control files, without having to forbid
extension and version names from containing any dashes.  We do have to
forbid them from containing double dashes or leading/trailing dashes,
but neither restriction is likely to bother anyone in practice.
Per discussion, this seems like a better solution overall than the
original design.

format.

Modify PQescapeStringConn() docs to be consisent with other escaping
functions.

Add mention problems with pre-9.0 versions of libpq using not understanding
bytea hex format to the 9.0 release notes.

Backpatch to 9.0 docs.

This change causes a multi-step update sequence to behave exactly as if the
updates had been commanded one at a time, including updating the "requires"
dependencies afresh at each step.  The initial implementation took the
shortcut of examining only the final target version's "requires" and
changing the catalog entry but once.  But on reflection that's a bad idea,
since it could lead to executing old update scripts under conditions
different than they were designed/tested for.  Better to expend a few extra
cycles and avoid any surprises.

In the same spirit, if a CREATE EXTENSION FROM operation involves applying
a series of update files, it will act as though the CREATE had first been
done using the initial script's target version and then the additional
scripts were invoked with ALTER EXTENSION UPDATE.

I also removed the restriction about not changing encoding in secondary
control files.  The new rule is that a script is assumed to be in whatever
encoding the control file(s) specify for its target version.  Since this
reimplementation causes us to read each intermediate version's control
file, there's no longer any uncertainty about which encoding setting would
get applied.

relative, by creating a function path_is_relative_and_below_cwd() to
check for specific requirements.  It is unclear if this fixes a security
problem or not but the new code is more robust.

- collowner field
- CREATE COLLATION
- ALTER COLLATION
- DROP COLLATION
- COMMENT ON COLLATION
- integration with extensions
- pg_dump support for the above
- dependency management
- psql tab completion
- psql \dO command

When the old type is binary coercible to the new type and the using
clause does not change the column contents, we can avoid a full table
rewrite, though any indexes on the affected columns will still need
to be rebuilt.  This applies, for example, when changing a varchar
column to be of type text.

The prior coding assumed that the set of operations that force a
rewrite is identical to the set of operations that must be propagated
to tables making use of the affected table's rowtype.  This is
no longer true: even though the tuples in those tables wouldn't
need to be modified, the data type change invalidate indexes built
using those composite type columns.  Indexes on the table we're
actually modifying can be invalidated too, of course, but the
existing machinery is sufficient to handle that case.

Along the way, add some debugging messages that make it possible
to understand what operations ALTER TABLE is actually performing
in these cases.

Noah Misch and Robert Haas

Arrange for the control files to be in $SHAREDIR/extension not
$SHAREDIR/contrib, since we're generally trying to deprecate the term
"contrib" and this is a once-in-many-moons opportunity to get rid of it in
install paths.  Fix PGXS to install the $EXTENSION file into that directory
no matter what MODULEDIR is set to; a nondefault MODULEDIR should only
affect the script and secondary extension files.  Fix the control file
directory parameter to be interpreted relative to $SHAREDIR, to avoid a
surprising disconnect between how you specify that and what you set
MODULEDIR to.

Per discussion with David Wheeler.

This follows recent discussions, so it's quite a bit different from
Dimitri's original.  There will probably be more changes once we get a bit
of experience with it, but let's get it in and start playing with it.

This is still just core code.  I'll start converting contrib modules
shortly.

Dimitri Fontaine and Tom Lane