Re: After ~Crash Sequence not correct

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Mikheev, Vadim" <vmikheev@SECTORBASE.COM>
Cc: "Henshall, Stuart - WCP" <SHenshall@westcountrypublications.co.uk>, pgsql-bugs@postgreSQL.org
Date: 2001-12-19T18:48:33Z
Lists: pgsql-bugs
"Mikheev, Vadim" <vmikheev@SECTORBASE.COM> writes:
> It was made to avoid WAL-loging on each nextval call, ie it should work
> like OID pre-fetching: value stored in WAL must always "exceed" values
> returned by nextval so on the after-crash-restart sequence should be
> advanced to value which was never returned by nextval (for non-cycled
> sequences). Maybe I made some mistakes in implementation?

Oh, okay.  What I saw was that the next nextval() after restart was
higher than what I was expecting; but that's correct given the prefetch
behavior.

But we've seen several reports wherein the value appeared to go
backwards after a crash.

Stuart, you weren't running with -F (fsync off) by any chance, were you?

			regards, tom lane