Re: What's the XID?

On Thu, 27 Dec 2007, Tom Lane wrote:

> Jeff Frost <jeff@frostconsultingllc.com> writes:
>> On Thu, 27 Dec 2007, Tom Lane wrote:
>>> But note that as of 8.3, SELECT-only transactions won't acquire an
>>> XID and hence won't advance the counter.  So if you're thinking of
>>> writing code that depends on that behavior, don't.
>
>> So, the new XID counter won't advance unless there's at least one
>> INSERT/UPDATE/DELETE in the transaction?  Does it also update for SELECTs that
>> call a function which does some write activity?
>
> Any "write" activity causes an XID to be acquired.
>
>> Is there a new counter (or old one that I don't know about) that keeps track
>> of the SELECT-only transactions?
>
> There's no global counter.  There's a backend-local "virtual transaction
> id" counter.
>

That's a drag as I have quite a few clients who graph the xacts/sec with MRTG.
Most of these clients have read heavy workloads and it would be great to be
able to graph read vs write xacts, but a drag if you have no visibility into
the read xacts.


--
Jeff Frost, Owner     <jeff@frostconsultingllc.com>
Frost Consulting, LLC     http://www.frostconsultingllc.com/
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