| From: | "Pavan Deolasee" <pavan(dot)deolasee(at)gmail(dot)com> |
|---|---|
| To: | "Heikki Linnakangas" <heikki(at)enterprisedb(dot)com> |
| Cc: | "ITAGAKI Takahiro" <itagaki(dot)takahiro(at)oss(dot)ntt(dot)co(dot)jp>, "Martijn van Oosterhout" <kleptog(at)svana(dot)org>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: Free space management within heap page |
| Date: | 2007-01-23 13:43:39 |
| Message-ID: | 2e78013d0701230543k54087265tce71bf74155dc8b1@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 1/23/07, Heikki Linnakangas <heikki(at)enterprisedb(dot)com> wrote:
>
> ITAGAKI Takahiro wrote:
> > BLCKSZ is typically 8192 bytes and sizeof(ItemPointerData) is 4 bytes.
> > 1/4 comes from 8192 / 4 = 2048. If we allow zero-size tuples, the line
> > pointers area can bloat up to the ratio. We have tuples no less than
> > 32 bytes-size, so the area is restricted 256 bytes now.
>
> sizeof(ItemPointerData) == 6 bytes
>
>
I guess ITAGAKI meant sizeof(ItemIdData) which is 4 bytes. Thats the data
type
for the line pointer.
Thanks,
Pavan
EnterpriseDB http://www.enterprisedb.com
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Heikki Linnakangas | 2007-01-23 13:52:07 | Re: Piggybacking vacuum I/O |
| Previous Message | Pavan Deolasee | 2007-01-23 13:39:56 | Re: Piggybacking vacuum I/O |