* Changes the APIs to the timezone functions to take a pg_tz pointer as
an argument, representing the timezone to use for the selected
operation.

* Adds a global_timezone variable that represents the current timezone
in the backend as set by SET TIMEZONE (or guc, or env, etc).

* Implements a hash-table cache of loaded tables, so we don't have to
read and parse the TZ file everytime we change a timezone. While not
necesasry now (we don't change timezones very often), I beleive this
will be necessary (or at least good) when "multiple timezones in the
same query" is eventually implemented. And code-wise, this was the time
to do it.


There are no user-visible changes at this time. Implementing the
"multiple zones in one query" is a later step...

This also gets rid of some of the cruft needed to "back out a timezone
change", since we previously couldn't check a timezone unless it was
activated first.

Passes regression tests on win32, linux (slackware 10) and solaris x86.

Magnus Hagander

than simply passing it down to pg_dump.  Else, version-related failures
in pg_dumpall itself generate unhelpful error messages.

> * Compress WAL entries [wal]

pfree'able result, since some callers expect to be able to pfree
the result of a pass-by-reference function.  Per report from Chris Trawick.

<   failure.
>   failure.  This could be triggered by a user command or a timer.
< * Force archiving of partially-full WAL files when pg_stop_backup() is
<   called or the server is stopped
> * Automatically force archiving of partially-filled WAL files when
>   pg_stop_backup() is called or the server is stopped

before you are done.

>
>   Doing this will allow administrators to know more easily when the
>   archive contins all the files needed for point-in-time recovery.

> * Force archiving of partially-full WAL files when pg_stop_backup() is
>   called or the server is stopped

Not connected to anything useful yet ...

return just a single tuple at a time.  Currently the only such node
type is Hash, but I expect we will soon have indexscans that can return
tuple bitmaps.  A side benefit is that EXPLAIN ANALYZE now shows the
correct tuple count for a Hash node.

critical and noncritical contexts (an example of noncritical being
post-checkpoint removal of dead xlog segments).  In the critical cases
the CRIT_SECTION mechanism will cause ERROR to be promoted to PANIC
anyway, and in the noncritical cases we shouldn't let an error take
down the entire database.  Arguably there should be *no* explicit
PANIC errors in this module, only more START/END_CRIT_SECTION calls,
but I didn't go that far.  (Yet.)

when recycling a large number of xlog segments during checkpoint.
The former behavior searched from the same start point each time,
requiring O(checkpoint_segments^2) stat() calls to relocate all the
segments.  Instead keep track of where we stopped last time through.

which induced bug #1597 in addition to having several other misbehaviors
(like labeling the dump with a completion time having nothing to do with
reality).  Instead just print out the desired strings where RestoreArchive
was already emitting the 'PostgreSQL database dump' and
'PostgreSQL database dump complete' strings.

required by modern versions of GCC.

Niels Breet

> * -Use indexes for MIN() and MAX()

assuming comparison of atttypid is sufficient.  In a dropped column
atttypid will be 0, and we'd better check the physical-storage data
to make sure the tupdescs are physically compatible.
I do not believe there is a real risk before 8.0, since before that
we only used this routine to compare successive states of the tupdesc
for a particular relation.  But 8.0's typcache.c might be comparing
arbitrary tupdescs so we'd better play it safer.

fit of over-optimization.

isn't presently set up to pass them an expected tuple descriptor.  Bug has
been there since 7.3 but was just recently reported by Thomas Hallgren.

whose keys are OIDs.  The only one that looks particularly performance
critical is the relcache hashtable, but as long as we've got the function
we may as well use it wherever it's applicable.

indexes.  Replace all heap_openr and index_openr calls by heap_open
and index_open.  Remove runtime lookups of catalog OID numbers in
various places.  Remove relcache's support for looking up system
catalogs by name.  Bulky but mostly very boring patch ...

indexes.  Extend the macros in include/catalog/*.h to carry the info
about hand-assigned OIDs, and adjust the genbki script and bootstrap
code to make the relations actually get those OIDs.  Remove the small
number of RelOid_pg_foo macros that we had in favor of a complete
set named like the catname.h and indexing.h macros.  Next phase will
get rid of internal use of names for looking up catalogs and indexes;
but this completes the changes forcing an initdb, so it looks like a
good place to commit.
Along the way, I made the shared relations (pg_database etc) not be
'bootstrap' relations any more, so as to reduce the number of hardwired
entries and simplify changing those relations in future.  I'm not
sure whether they ever really needed to be handled as bootstrap
relations, but it seems to work fine to not do so now.

avoid encroaching on the 'user' range of OIDs by allowing automatic
OID assignment to use values below 16k until we reach normal operation.

initdb not forced since this doesn't make any incompatible change;
however a lot of stuff will have different OIDs after your next initdb.

of just a relation OID, thereby not having to open the relation for itself.
This actually saves code rather than adding it for most of the existing
callers, which had the rel open already.  The main point though is to be
able to use this rather than plain addRangeTableEntry in setTargetTable,
thus saving one relation_openrv/relation_close cycle for every INSERT,
UPDATE, or DELETE.  Seems to provide a several percent win on simple
INSERTs.

On reflection, we ought to get rid of that mechanism entirely.