Re: BUG #15008: Need a pause

You are absolutely right !

Sorry for the noise here. Next time, I'll post on the user ML first.

Cheers,
Laurent

2018-01-12 10:39 GMT+01:00 Greg Clough <greg(dot)clough(at)ipreo(dot)com>:

> > The following bug has been logged on the website:
> >
> > Bug reference: 15008
> > Logged by: Laurent Martelli
> > Email address: martellilaurent(at)gmail(dot)com
> > PostgreSQL version: 9.6.6
> > Operating system: Debian 9.3
> > Description:
> >
> > I have a set of scripts I execute with psql, and for some reason, a
> query in one of them take forever (never had the patience to wait for more
> than 15 minutes), eating 1 CPU, unless I insert a pause (sleep 60) before
> that script, and then it only takes a few seconds.
> >
> > It only occurs when the tables we operate on have a sufficient number of
> rows. When we do "unit" tests with a subset of the data, it all goes
> smoothly.
> >
> > Please, tell me what additional information I can provide to help fix
> this.
>
> It sounds like you're bulk-loading rows, and not updating the table
> statistics before running a query. The pause may give autovacuum time to
> find and analyze the table so you get the correct query plan. I'd suggest
> you modify your script to add EXPLAIN ANALYZE to your query and then run it
> with and without the pause. Probably you'll find one is doing a full table
> scan, and the other is using an index.
>
> More than likely you will need to add an "ANALYZE table_name;" into your
> script in place of the pause
>
> Greg Clough
> Senior Technology Engineer
> O | +44 (0) 20 7665 9787
> M | +44 (0) 7803 142 292
>
> Ipreo
> Castle House | 37-35 Paul St | London EC2A 4LS
>

--
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