Re: Always truncate segments before unlink

Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Truncating seems like an ugly kluge that's not fixing the real problem.
> Why are there open descriptors for a dropped relation? They should all
> get closed as a consequence of relcache flush.

Relcache will be flushed at the next command, but there could be some
*idle backends* kept by connection pooling. They won't close dropped files
until shared cache invalidation queue are almost filled, that might take
long time.

There might be another solution that we send PROCSIG_CATCHUP_INTERRUPT
signal not only on the threshold of queue length but also on timeout,
where the signal is sent when we have some old messages in the queue
longer than 30sec - 1min.

Regards,
---
Takahiro Itagaki
NTT Open Source Software Center