"Sailer, Denis (YBUSA-CDR)" <Denis.Sailer@Yellowbook.com> writes:
> The following errors also showed up. So my question is why does the
> failure of CREATE INDEX cause all my connections to be terminated and
> the database to go into recovery mode? Sounds kind of drastic.
Not having any xlog space is fatal across-the-board: there is no place
to log anybody's transactions, not just the CREATE INDEX.
However, with reasonable checkpointing parameters this shouldn't happen
because checkpoints will occur frequently enough to reclaim the xlog
space. I believe you got bit by the 7.4 problem that allows checkpoints
to get blocked by CREATE INDEX operations. This is fixed in 8.0:
2004-06-02 13:28 tgl
* src/: backend/access/nbtree/nbtpage.c,
backend/access/nbtree/nbtree.c, backend/access/nbtree/nbtsort.c,
backend/access/nbtree/nbtxlog.c, backend/storage/smgr/md.c,
backend/storage/smgr/smgr.c, include/access/nbtree.h,
include/storage/smgr.h: Adjust btree index build to not use shared
buffers, thereby avoiding the locking conflict against concurrent
CHECKPOINT that was discussed a few weeks ago. Also, if not using
WAL archiving (which is always true ATM but won't be if PITR makes
it into this release), there's no need to WAL-log the index build
process; it's sufficient to force-fsync the completed index before
commit. This seems to gain about a factor of 2 in my tests, which
is consistent with writing half as much data. I did not try it
with WAL on a separate drive though --- probably the gain would be
a lot less in that scenario.
> Finally can someone give me a calculation that would tell me how much
> log space the CREATE INDEX command is going to take?
About as much as the finished index will occupy, which you did not give
enough information to estimate.
> I still need to
> get the index created with the system I have.
You might consider updating to 8.0 instead...
regards, tom lane
