postgresql/src/backend/utils
Tom Lane 895a94de6d Avoid incrementing the CommandCounter when CommandCounterIncrement is called
but no database changes have been made since the last CommandCounterIncrement.
This should result in a significant improvement in the number of "commands"
that can typically be performed within a transaction before hitting the 2^32
CommandId size limit.  In particular this buys back (and more) the possible
adverse consequences of my previous patch to fix plan caching behavior.

The implementation requires tracking whether the current CommandCounter
value has been "used" to mark any tuples.  CommandCounter values stored into
snapshots are presumed not to be used for this purpose.  This requires some
small executor changes, since the executor used to conflate the curcid of
the snapshot it was using with the command ID to mark output tuples with.
Separating these concepts allows some small simplifications in executor APIs.

Something for the TODO list: look into having CommandCounterIncrement not do
AcceptInvalidationMessages.  It seems fairly bogus to be doing it there,
but exactly where to do it instead isn't clear, and I'm disinclined to mess
with asynchronous behavior during late beta.
2007-11-30 21:22:54 +00:00
..
adt Make a cleanup pass over error reports in tsearch code. Use ereport 2007-11-28 21:56:30 +00:00
cache Avoid incrementing the CommandCounter when CommandCounterIncrement is called 2007-11-30 21:22:54 +00:00
error pgindent run for 8.3. 2007-11-15 21:14:46 +00:00
fmgr pgindent run for 8.3. 2007-11-15 21:14:46 +00:00
hash pgindent run for 8.3. 2007-11-15 21:14:46 +00:00
init pgindent run for 8.3. 2007-11-15 21:14:46 +00:00
mb Cleanup for new else/comment handling. 2007-11-16 01:11:04 +00:00
misc pgindent run for 8.3. 2007-11-15 21:14:46 +00:00
mmgr Re-run pgindent with updated list of typedefs. (Updated README should 2007-11-15 22:25:18 +00:00
resowner Re-run pgindent with updated list of typedefs. (Updated README should 2007-11-15 22:25:18 +00:00
sort pgindent run for 8.3. 2007-11-15 21:14:46 +00:00
time Avoid incrementing the CommandCounter when CommandCounterIncrement is called 2007-11-30 21:22:54 +00:00
.cvsignore Cleanup to ensure good state of derived files in tarballs. 2000-06-09 02:38:36 +00:00
Gen_fmgrtab.sh Implement function-local GUC parameter settings, as per recent discussion. 2007-09-03 00:39:26 +00:00
Makefile Replace useless uses of := by = in makefiles. 2007-02-09 15:56:00 +00:00
probes.d DTrace support, with a small initial set of probes 2006-07-24 16:32:45 +00:00