Re: MaxOffsetNumber versus MaxHeapTuplesPerPage - Mailing list pgsql-hackers

From Zdenek Kotala
Subject Re: MaxOffsetNumber versus MaxHeapTuplesPerPage
Date
Msg-id 472078E1.6000804@sun.com
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In response to Re: MaxOffsetNumber versus MaxHeapTuplesPerPage  (Heikki Linnakangas <heikki@enterprisedb.com>)
List pgsql-hackers
Heikki Linnakangas wrote:
> Zdenek Kotala wrote:
>> Is there any reason to have both these macros? By my opinion
>> MaxHeapTuplesPerPage is more accurate and it should replace all
>> MaxOffsetNumber occurrence.
> 
> We use MaxOffsetNumber with index pages as well.

I forgot to indexes, but there is MaxIndexTuplesPerPage which is also 
better estimation for indexes.

> At quick glance, the only places I can see where we could replace
> MaxOffsetNumber with MaxHeapTuplesPerPage, are in vacuum.c and
> vacuumlazy.c, where we allocate arrays big enough to hold potentially a
> full page's worth of tuples. We could change those, but it's hardly
> worth the trouble.

Yes, it is a cleanup (maybe reduce some memory requirements), but I 
think is better to reduce different macros to avoid future problem, when 
somebody forget changes all of these macros.
    Zdenek




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