Extracted from a much larger patch by Shigeru Hanada.

Add ERRCODE_INVALID_PASSWORD sqlstate error code.

support any indexable commutative operator, not just equality.  Two rows
violate the exclusion constraint if "row1.col OP row2.col" is TRUE for
each of the columns in the constraint.

Jeff Davis, reviewed by Robert Haas

unused nonstandard error code that was perhaps intended for this but never
used.

Hitoshi Harada, with some kibitzing from Heikki and Tom.

There are some unimplemented aspects: recursive queries must use UNION ALL
(should allow UNION too), and we don't have SEARCH or CYCLE clauses.
These might or might not get done for 8.4, but even without them it's a
pretty useful feature.

There are also a couple of small loose ends and definitional quibbles,
which I'll send a memo about to pgsql-hackers shortly.  But let's land
the patch now so we can get on with other development.

Yoshiyuki Asaba, with lots of help from Tatsuo Ishii and Tom Lane

Pavel Stehule

observe the xmloption.

Reorganize the representation of the XML option in the parse tree and the
API to make it easier to manage and understand.

Add regression tests for parsing back XML expressions.

back-stamped for this.

SQLSTATEs, fix some documentation problems.

with main, avoid using a SQL-defined SQLSTATE for what is most definitely
not a SQL-compatible error condition, fix documentation omissions,
adhere to message style guidelines, don't use two GUC_REPORT variables
when one is sufficient.  Nothing done about pg_dump issues.

should have been caught by the src/tools/copyright script ... why
weren't they?

to unreserved keyword, use ereport not elog, assign a separate error code
for 'could not obtain lock' so that applications will be able to detect
that case cleanly.

There are still some things that need refinement; in particular I fear
that the recognized set of error condition names probably has little in
common with what Oracle recognizes.  But it's a start.

SAVEPOINT/RELEASE/ROLLBACK-TO syntax.  (Alvaro)
Cause COMMIT of a failed transaction to report ROLLBACK instead of
COMMIT in its command tag.  (Tom)
Fix a few loose ends in the nested-transactions stuff.

of bug report #1150.  Also, arrange that the object owner's irrevocable
grant-option permissions are handled implicitly by the system rather than
being listed in the ACL as self-granted rights (which was wrong anyway).
I did not take the further step of showing these permissions in an
explicit 'granted by _SYSTEM' ACL entry, as that seemed more likely to
bollix up existing clients than to do anything really useful.  It's still
a possible future direction, though.

error codes for certain error conditions, as specified by SQL2003.

a variant of the function for the 'numeric' datatype; it would be possible
to add additional variants for other datatypes, but I haven't done so yet.

This commit includes regression tests and minimal documentation; if we
want developers to actually use this function in applications, we'll
probably need to document what it does more fully.

-patches.

float8 types. This begins the deprecation of this feature: in 7.6,
this input will be rejected.

Also added a new error code for warnings about deprecated features,
and updated the regression tests.

make sure the $Id tags are converted to $PostgreSQL as well ...

now able to cope with assigning new relfilenode values to nailed-in-cache
indexes, so they can be reindexed using the fully crash-safe method.  This
leaves only shared system indexes as special cases.  Remove the 'index
deactivation' code, since it provides no useful protection in the shared-
index case.  Require reindexing of shared indexes to be done in standalone
mode, but remove other restrictions on REINDEX.  -P (IgnoreSystemIndexes)
now prevents using indexes for lookups, but does not disable index updates.
It is therefore safe to allow from PGOPTIONS.  Upshot: reindexing system catalogs
can be done without a standalone backend for all cases except
shared catalogs.

lumping them into ERRCODE_UNDEFINED_OBJECT/ERRCODE_DUPLICATE_OBJECT.
This seems reasonable since 'object' was meant to refer to 'object in the
database' and a file is outside the database.  Per request from Dave
Cramer.

the bulk of the heavy lifting ...

Along the way, fix some logic problems in pgstat_initstats, notably the
bogus assumption that malloc returns zeroed memory.