Re: Should a DB vacuum use up a lot of space ?

>> I am seeing something weird though (again, this is v9.1): after my database became usable again, I started getting the 10M warning on template0. So I made it connectable and ran VACUUM
>>FREEZE on it and made it unconnectable again. That resolve the warning.
>>
>> However, I see the “age” keeps increasing on that database as I ran queries on my own db. Yesterday the age was 32 and now it’s already 77933902
>Just to be sure you are talking about template0?
Yes, I am

>> Is that to be expected ? I didn’t expect it
>As I understand it;
>
> 1) xid's are global to the cluster.
> 2) age(xid) measures the difference between the latest global xid to
> whatever xid you supply it.
> 3) age(datfrozenxid) measures the difference between the minimum value
> for the table frozen ids in a particular database and the latest global xid.
> 4) template0 has a datfrozenxid so there is something for age(xid) to
> compute, it just does not mean anything as long as template0 is really a
> read-only database. In other words template0 is not actually
> contributing any transactions to the consumption of the global store of
> xids.
Yes, I understand. I’m just worried that if I see the WARNING for the 100M mark, I’m afraid when it gets to the 1M mark on that database it will shut down the cluster.

More weirdness this afternoon : the wraparound ERROR showed up again even though I have trouble believing I burned through so many transactions in under a day. But let’s assume I did, here is what I noticed

1) I vacuumed all other databases. For everyone of those, the age went down to 50M instead of zero. Is that normal ?
2) The only database that didn’t work on was template0 (the age did not change). It did work on template1

Should I suspect something fishy going on ?

Thanks