before reporting a transaction committed.  Data consistency is still
guaranteed (unlike setting fsync = off), but a crash may lose the effects
of the last few transactions.  Patch by Simon, some editorialization by Tom.

back-stamped for this.

comment line where output as too long, and update typedefs for /lib
directory.  Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).

Backpatch to 8.1.X.

hacking by Alvaro Herrera and Tom Lane.

the AMI_OVERRIDE flag.  The fact that TransactionLogFetch treats
BootstrapTransactionId as always committed is sufficient to make
bootstrap work, and getting rid of extra tests in heavily used code
paths seems like a win.  The files produced by initdb are demonstrably
the same after this change.

Tag appropriate files for rc3

Also performed an initial run through of upgrading our Copyright date to
extend to 2005 ... first run here was very simple ... change everything
where: grep 1996-2004 && the word 'Copyright' ... scanned through the
generated list with 'less' first, and after, to make sure that I only
picked up the right entries ...

pg_subtrans --- what we need is the oldest xmin of any snapshot in use
in the current top transaction.  Introduce a new variable TransactionXmin
to play this role.  Fixes intermittent regression failure reported by
Neil Conway.

TransactionIdDidCommit.

RecentXmin (== MyProc->xmin).  This ensures that it will be safe to
truncate pg_subtrans at RecentGlobalXmin, which should largely eliminate
any fear of bloat.  Along the way, eliminate SubTransXidsHaveCommonAncestor,
which isn't really needed and could not give a trustworthy result anyway
under the lookback restriction.
In an unrelated but nearby change, #ifdef out GetUndoRecPtr, which has
been dead code since 2001 and seems unlikely to ever be resurrected.

performance front, but with feature freeze upon us I think it's time to
drive a stake in the ground and say that this will be in 7.5.

Alvaro Herrera, with some help from Tom Lane.

$Header: -> $PostgreSQL Changes ...

> Changes to avoid collisions with WIN32 & MFC names...
> 1.  Renamed:
>       a.  PROC => PGPROC
>       b.  GetUserName() => GetUserNameFromId()
>       c.  GetCurrentTime() => GetCurrentDateTime()
>       d.  IGNORE => IGNORE_DTF in include/utils/datetime.h & utils/adt/datetim
>
> 2.  Added _P to some lex/yacc tokens:
>       CONST, CHAR, DELETE, FLOAT, GROUP, IN, OUT

Jan

and just slow down normal operations (only fractionally, but a cycle saved
is a cycle earned).  Improve documentation of AMI_OVERRIDE behavior.

initdb/regression tests pass.

tests pass.

documentation to come, but the code is all here.  initdb forced.

buffer manager with 'pg_clog', a specialized access method modeled
on pg_xlog.  This simplifies startup (don't need to play games to
open pg_log; among other things, OverrideTransactionSystem goes away),
should improve performance a little, and opens the door to recycling
commit log space by removing no-longer-needed segments of the commit
log.  Actual recycling is not there yet, but I felt I should commit
this part separately since it'd still be useful if we chose not to
do transaction ID wraparound.

(TransactionIdPrecedes, TransactionIdFollows, etc).  First step on the
way to transaction ID wrap solution ...

validity checking rules for VACUUM.  Make some other rearrangements of the
VACUUM code to allow more code to be shared between full and lazy VACUUM.
Minor code cleanups and added comments for TransactionId manipulations.

forced.

NEXTXID isn't really necessary, per previous discussion in pghackers,
but I mulishy insisted we should put it in anyway.  Mea culpa.

* Store two past checkpoint locations, not just one, in pg_control.
  On startup, we fall back to the older checkpoint if the newer one
  is unreadable.  Also, a physical copy of the newest checkpoint record
  is kept in pg_control for possible use in disaster recovery (ie,
  complete loss of pg_xlog).  Also add a version number for pg_control
  itself.  Remove archdir from pg_control; it ought to be a GUC
  parameter, not a special case (not that it's implemented yet anyway).

* Suppress successive checkpoint records when nothing has been entered
  in the WAL log since the last one.  This is not so much to avoid I/O
  as to make it actually useful to keep track of the last two
  checkpoints.  If the things are right next to each other then there's
  not a lot of redundancy gained...

* Change CRC scheme to a true 64-bit CRC, not a pair of 32-bit CRCs
  on alternate bytes.  Polynomial borrowed from ECMA DLT1 standard.

* Fix XLOG record length handling so that it will work at BLCKSZ = 32k.

* Change XID allocation to work more like OID allocation.  (This is of
  dubious necessity, but I think it's a good idea anyway.)

* Fix a number of minor bugs, such as off-by-one logic for XLOG file
  wraparound at the 4 gig mark.

* Add documentation and clean up some coding infelicities; move file
  format declarations out to include files where planned contrib
  utilities can get at them.

* Checkpoint will now occur every CHECKPOINT_SEGMENTS log segments or
  every CHECKPOINT_TIMEOUT seconds, whichever comes first.  It is also
  possible to force a checkpoint by sending SIGUSR1 to the postmaster
  (undocumented feature...)

* Defend against kill -9 postmaster by storing shmem block's key and ID
  in postmaster.pid lockfile, and checking at startup to ensure that no
  processes are still connected to old shmem block (if it still exists).

* Switch backends to accept SIGQUIT rather than SIGUSR1 for emergency
  stop, for symmetry with postmaster and xlog utilities.  Clean up signal
  handling in bootstrap.c so that xlog utilities launched by postmaster
  will react to signals better.

* Standalone bootstrap now grabs lockfile in target directory, as added
  insurance against running it in parallel with live postmaster.

These two routines will now ALWAYS elog() on failure, whether you ask for
a lock or not.  If you really want to get a NULL return on failure, call
the new routines heap_open_nofail()/heap_openr_nofail().  By my count there
are only about three places that actually want that behavior.  There were
rather more than three places that were missing the check they needed to
make under the old convention :-(.

  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc

to all files copyright Regents of Berkeley.  Man, that's a lot of files.

additional argument specifying the kind of lock to acquire/release (or
'NoLock' to do no lock processing).  Ensure that all relations are locked
with some appropriate lock level before being examined --- this ensures
that relevant shared-inval messages have been processed and should prevent
problems caused by concurrent VACUUM.  Fix several bugs having to do with
mismatched increment/decrement of relation ref count and mismatched
heap_open/close (which amounts to the same thing).  A bogus ref count on
a relation doesn't matter much *unless* a SI Inval message happens to
arrive at the wrong time, which is probably why we got away with this
sloppiness for so long.  Repair missing grab of AccessExclusiveLock in
DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi.
Recommend 'make clean all' after pulling this update; I modified the
Relation struct layout slightly.
Will post further discussion to pghackers list shortly.

Also, move responsibility for calling vc_abort into main xact.c list of
things-to-call-at-abort.  What in the world was it doing down inside of
TransactionIdAbort()?