Re: What's the XID?

Andrew Sullivan <ajs@crankycanuck.ca> writes:
> On Wed, Dec 26, 2007 at 05:48:14PM -0800, ivan.hou wrote:
>> if i executed "select * from mydb" twice, the XID wil be increased by 2

> Yep.  Whereas if you did

>     BEGIN;
>     SELECT 1;
>     SELECT 1;
>     COMMIT;

> the xid would be increased by 1.

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.

            regards, tom lane