Re: SSI slows down over time

On 14/04/2014 10:14 AM, Kevin Grittner wrote:
> Ryan Johnson <ryan.johnson@cs.utoronto.ca> wrote:
>
>> every time I shut down a database and bring it back up, SSI seems
>> to go slower.
> There's one thing to rule out up front -- that would be a
> long-lived prepared transaction.
>
> Please post the output of these queries:
>
> select version();
> show max_prepared_transactions;
> select * from pg_prepared_xacts;
Hmm. My machine was rebooted over the weekend for Heartbleed patches, so
I'll have to re-build the database and fire off enough runs to repro.
There are some disadvantages to keeping it in tmpfs...

Meanwhile, a quick question: what factors might cause a prepared
transaction to exist in the first place? I'm running a single-node db,
and I've had only normal database shutdowns, so I wouldn't have expected
any.

Thoughts?
Ryan