Re: Re: [COMMITTERS] pgsql: Introduce WAL records to log reuse of btree pages, allowing

Simon Riggs <simon@2ndQuadrant.com> writes:
> On Thu, 2010-02-18 at 14:23 +0200, Heikki Linnakangas wrote:
>> A straightforward way to fix that is to WAL-log the real xid in the
>> XLOG_BTREE_DELETE_PAGE records, instead of resetting it to
>> FrozenTransactionId.

> An even simpler way would be to reset the value to latestCompletedXid
> during btree_xlog_delete_page(). That touches less code. I doubt it will
> make much difference to conflict recovery, since if pages are being
> deleted then btree delete records are likely to be frequent and will
> have already killed long running queries.

I'm a bit concerned about XID wraparound if the value doesn't get reset
to FrozenTransactionId.  There's no guarantee the page will get reused
promptly ...
        regards, tom lane