Re: vacuum vs open transactions

On Wednesday January 12 2005 11:30, Michael Fuhr wrote:
> On Wed, Jan 12, 2005 at 11:49:12AM -0700, Ed L. wrote:
> > Is it possible via SQL query to tell how long a transaction has been
> > open?
>
> I'm not aware of a way to find out when a transaction started, but
> if you have stats_command_string enabled then you can query
> pg_stat_activity to see when a session's current query started.

Yes, I see that in 7.4 (not in 7.3). But my purpose would be to remotely
identify long-open transactions that are causing table bloat by making
vacuum fail to reclaim space, so it seems I need the transaction start
time, not query start time. Most likely this situation occurs when 1)
someone starts a transaction in psql and then leaves it there, or 2) an
application opens a transaction prior to getting user input.

Ed