Re: autovacuum truncate exclusive lock round two

Jan Wieck wrote:

> In the original code, the maximum delay that autovacuum can cause by
> holding the exclusive lock is one deadlock_timeout (default 1s). It
> would appear reasonable to me to use max(deadlock_timeout/10,10ms)
> as the interval to check for a conflicting lock request. For another
> transaction that needs to access the table this is 10 times faster
> than it is now and still guarantees that autovacuum will make some
> progress with the truncate.

So you would be calling GetCurrentTimestamp() continuously?  Since you
mentioned adding a vacuum delay point I wonder if it would make sense to
test for lockers each time it would consider going to sleep, instead.
(One hazard to keep in mind is the case where no vacuum delay is
configured.)

--
Álvaro Herrera                http://www.2ndQuadrant.com/
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