| From: | "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov> |
|---|---|
| To: | "Heikki Linnakangas" <heikki(dot)linnakangas(at)enterprisedb(dot)com> |
| Cc: | <pgsql-hackers(at)postgresql(dot)org>,<rhaas(at)postgresql(dot)org> |
| Subject: | Re: Re: [COMMITTERS] pgsql: Adjust OLDSERXID_MAX_PAGE based on BLCKSZ. |
| Date: | 2011-07-08 13:45:46 |
| Message-ID: | 4E16C3BA020000250003F0F3@gw.wicourts.gov |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> On 08.07.2011 15:22, Kevin Grittner wrote:
>> MaxTransactionId / OLDSERXID_ENTRIESPERPAGE
>
> Hmm, that seems more correct to me anyway. We are trying to
> calculate which page xid MaxTransactionId would be stored on, if
> the SLRU didn't have a size limit. You calculate that with simply
> MaxTransactionId / OLDSERXID_ENTRIESPERPAGE.
Good point. The old calculation was finding the page before the
page which would contain the first out-of-bound entry. As long as
these numbers are all powers of 2 that's the same, but (besides the
overflow issue) it's not as clear.
On the off chance that this saves someone any work, trivial patch
attached.
-Kevin
| Attachment | Content-Type | Size |
|---|---|---|
| ssi-maxpage-rounding.patch | text/plain | 751 bytes |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Peter Eisentraut | 2011-07-08 13:50:44 | Re: Full GUID support |
| Previous Message | Martin Pihlak | 2011-07-08 13:36:00 | Re: libpq SSL with non-blocking sockets |