Re: Another idea for dealing with cmin/cmax
| От | Heikki Linnakangas |
|---|---|
| Тема | Re: Another idea for dealing with cmin/cmax |
| Дата | |
| Msg-id | 451CEE71.40600@enterprisedb.com обсуждение исходный текст |
| Ответ на | Re: Another idea for dealing with cmin/cmax (Martijn van Oosterhout <kleptog@svana.org>) |
| Ответы |
Re: Another idea for dealing with cmin/cmax
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| Список | pgsql-hackers |
Martijn van Oosterhout wrote: > On Fri, Sep 29, 2006 at 09:35:31AM +0100, Heikki Linnakangas wrote: >> We could get rid of t_hoff, because we should always be able to >> calculate the header size. Then we're down to 18 bytes. > > Without t_hoff, how do you know the size of the null bitmap? You could > probably do it only if you assume the null bitmap, if present, always > covers all the columns... I think we assume that already. heap_form_tuple reserves space for the bitmap like this: if (hasnull) len += BITMAPLEN(numberOfAttributes); -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com
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