Re: Add visibility map information to pg_freespace.

On 26 June 2013 09:09, Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>wrote:

> - How about pageinspect?
>
> I proposed a simple representation format as a basis for
> discussion. Nevertheless, the VM pages has no more structure
> than a simple bit string. Given the VM info in pg_freespacemap,
> I've come in doubt of the necessity of vm_page_contnets() for
> the reason besides the orthogonality in the this extension's
> interface (which paid no attention before:-).
>

I don't think that will be needed, now I understand.

> - How about pgstattuple?
>
> It could even be said to be meaningful to add the number of
> not-all-visible pages or the ratio of it in the total pages..
>
> | postgres=# select * from pgstattuple('t');
> | -[ RECORD 1 ]----------------+---------
> | table_len | 88711168
> | tuple_count | 600001
> | tuple_len | 26400044
> | tuple_percent | 29.76
> | dead_tuple_count | 399999
> | dead_tuple_len | 17599956
> | dead_tuple_percent | 19.84
> | free_space | 33607960
> | free_percent | 37.88
> + not_all_visible_page_percent | 23.54
>
> # This column name looks too long, though.
>

Yes, please.

But name should be all_visible_percent.
Anybody that wants not_all_visible_percent can do the math.

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Simon Riggs http://www.2ndQuadrant.com/
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