Re: database must be vacuumed with <N> transactions

On Thu, Jun 25, 2015 at 8:49 AM, Dave Johansen <davejohansen(at)gmail(dot)com>
wrote:

> On Thu, Jun 25, 2015 at 8:49 AM, Dave Johansen <davejohansen(at)gmail(dot)com>
> wrote:
>
>>
>> http://www.postgresql.org/docs/8.4/static/routine-vacuuming.html#VACUUM-FOR-WRAPAROUND
>>
>> The database I work on started spitting out the following message last
>> night:
>> WARNING: database "ops" must be vacuumed within 9361597 transaction
>>
>> I ran VACUUM as soon as I got in, but then shortly after, it stopped
>> accepting transactions. I stopped the database and opened single user mode
>> to run VACUUM. So my questions are:
>> 1) How long should I expect this to take (database has about 5 TB of
>> data)?
>> 2) Is there a faster way to make the database be operational again?
>>
>
> Sorry for the multiple emails, but I forgot to mention that I'm using 8.4
> on RHEL 6.4.
>

Once the VACUUM was started to get the database back online, we did some
diagnostics and it appears that there was a VERY large number of
transactions done in the last few weeks and that was the source of this
problem. It appears that there's a txid_current() function (
http://www.postgresql.org/docs/8.4/static/functions-info.html#FUNCTIONS-TXID-SNAPSHOT
), but is there a way to get the XID for all open connections so we can
find the offending connection and fix the issue so this won't happen again?

Thanks,
Dave