Re: Measuring relation free space

On 07/11/11 10:20, Bernd Helmle wrote:
>
>
> --On 6. November 2011 01:08:11 -0200 Greg Smith <greg@2ndQuadrant.com> 
> wrote:
>
>> Attached patch adds a new function to the pageinspect extension for 
>> measuring
>> total free space, in either tables or indexes.
>
> I wonder if that should be done in the pgstattuple module, which 
> output some similar numbers.
>

Not meaning to disparage Greg's effort in any way, but I was thinking 
the same thing about pg_freespacemap. I have not checked what - if any 
differences there are in output, but it would be interesting to compare 
which of the various (3 at present) extensions with slightly overlapping 
areas of functionality should perhaps be merged.

I am guessing (at this point very much guessing) that pg_freespace map 
may return its data faster, as pageinspect is gonna have to grovel 
through all the pages for itself (whereas pg_freespacemap relies on 
using info from the ... free space map fork).

regards

Mark