Re: vacuum issues under load?

On Fri, 15 Jan 2010, Tom Lane wrote:

>> #0  0x00007f59a5d78ca7 in semop () from /lib/libc.so.6
>> #1  0x0000000000546656 in PGSemaphoreLock ()
>> #2  0x00000000005618ee in LockBufferForCleanup ()
>> #3  0x000000000045c8e2 in btbulkdelete ()
>
> OK, so it's trying to get an exclusive page-level lock on some page of
> the index.  The only thing that could block that for any long period is
> if some other process is sitting with an open indexscan.  Look around
> for processes that have been "idle in transaction" for a long time ...

There are some, but they've all been running less than a second. There's
no better place to look than pg_stat_activity, is there?