idea on consistency grounds, whether or not it really fixes bug #1831.
Michael Fuhr

insufficient paranoia in code that follows t_ctid links.  (We must do both
because even with VACUUM doing it properly, the intermediate state with
a dangling t_ctid link is visible concurrently during lazy VACUUM, and
could be seen afterwards if either type of VACUUM crashes partway through.)
Also try to improve documentation about what's going on.  Patch is a bit
bulky because passing the XMAX information around required changing the
APIs of some low-level heapam.c routines, but it's not conceptually very
complicated.  Per trouble report from Teodor and subsequent analysis.
This needs to be back-patched, but I'll do that after 8.1 beta is out.

the right to stand out.

or OFFSET clauses by using estimate_expression_value().  The main advantage
of this is that if the expression is a Param and we have a value for the
Param, we'll use that value rather than defaulting.  Also, fix some
thinkos in the logic for combining LIMIT/OFFSET with an externally
supplied tuple fraction (this covers cases like EXISTS(...LIMIT...)).
And make sure the results of all this are shown by EXPLAIN.  Per a
gripe from Merlin Moncure.

> 	o Remove unnecessary abstractions in pg_dump source code

> * -Prevent to_char() on interval from returning meaningless values

Fix to_char(interval) to return large year/month/day/hour values that
are larger than possible timestamp values.
Prevent to_char(interval) format specifications that make no sense, like
Month.
Clean up formatting.c code to more logically handle return lengths.

AbortTransaction.  This can happen if a backend's InitPostgres transaction
fails (eg, because the given username is invalid).  Per Alvaro.

integer with flags.

max_fsm_relations.

Run autoconf/autoheader in case someone forgot in the past.

anyway, and in assert-enabled builds you are likely to get an assertion
failure.  Backpatch as far as 7.3; 7.2 seems not to have the problem.

and creation columns to behave for Unix or Win32.

caused PL languages and handlers to be dumped ALWAYS, even in the face
of contrary --schema or --table switches.  Adopt a slightly saner
definition.

by forcing search_path to be just pg_catalog.

their OID parameter.  It was possible to crash the backend with
select array_in('{123}',0,0); because that would bypass the needed step
of initializing the workspace.  These seem to be the only two places
with a problem, though (record_in and record_recv don't have the issue,
and the other array functions aren't depending on user-supplied input).
Back-patch as far as 7.4; 7.3 does not have the bug.

working state, not fcinfo->context.  Silly oversight on my part in last
go-round of fixes.

(the stats system has always collected this info, but the views were
filtering it out).  Modify autovacuum so that over-threshold activity
in a toast table can trigger a VACUUM of the parent table, even if the
parent didn't appear to need vacuuming itself.  Per discussion a month
or so back about "short, wide tables".

so that it will correctly dump owners of objects owned by non-login roles.

they don't miss owners that are NOLOGIN.

other stuff; change \du and \dg to be role-aware (Stefan Kaltenbrunner).
Also make tab completion fetch the list of GUC variables from pg_settings
instead of having a hard-wired copy of the list (Tom Lane).

SearchCatCacheList and ReleaseCatCacheList.  Previously, we incremented
and decremented the refcounts of list member tuples along with the list
itself, but that's unnecessary, and very expensive when the list is big.
It's cheaper to change only the list refcount.  When we are considering
deleting a cache entry, we have to check not only its own refcount but
its parent list's ... but it's easy to arrange the code so that this
check is not made in any commonly-used paths, so the cost is really nil.
The bigger gain though is to refrain from DLMoveToFront'ing each individual
member tuple each time the list is referenced.  To keep some semblance
of fair space management, lists are just marked as used or not since the
last cache cleanout search, and we do a MoveToFront pass only when about
to run a cleanout.  In combination, these changes reduce the costs of
SearchCatCacheList and ReleaseCatCacheList from about 4.5% of pgbench
runtime to under 1%, according to my gprof results.

remember the output parameter set for himself.  It's a bit of a kluge
but fixing array_in to work in bootstrap mode looks worse.
I removed the separate pg_file_length() function, as it no longer has any
real notational advantage --- you can write (pg_stat_file(...)).length.

Marko Kreen