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Old 04-12-2008, 06:02 AM
Heikki Linnakangas
 
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Default Re: Another idea for dealing with cmin/cmax

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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