On 2/25/06, Christopher Browne <cbbrowne at ca.afilias.info> wrote:
> - This case points to my paranoia about TRUNCATE (expressed this
> afternoon on IRC) having some merit...
>
> Jan, I think the case Rod describes is a case that makes it mandatory
> for logswitch_finish() to exit without truncating if it sees any locks
> outstanding on the sl_log_n table in question; you could have the
> situation where a long running transaction has 1M tuples, not yet
> committed, sitting in sl_log_1.  They aren't visible as being live
> tuples, but they are NOT dead...

You can see if there are long-running queries from snapshot.

You can even tell in which sl_log table they can be with a bit
of accounting.

--
marko