Ow Mun Heng <Ow.Mun.Heng at wdc.com> writes:
> I learned how to manually force a logswitch. Then I wait, and wait for
> the delete to kick in so that my original log_* table gets the contents
> deleted.
>
> What's the algo behind this cleanup anyway?

It's in the code; generally, we consider switching logs if that seems
practical.  (If we are still processing a previous log switch, then it
ISN'T practical ;-)!)

It gets handled in the fairly asynchronous fashion so that we can be
pretty sure that it is safe to TRUNCATE the empty table, and don't
need to worry about that TRUNCATE causing other things to block.

This bit us, occasionally, with the predecessor eRServer system.  It
was not as careful about it's approach to using TRUNCATE, and that
would sometimes lead to application outages when a log table would be
locked by the TRUNCATE :-(.
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