Re: Stats for inheritance trees - Mailing list pgsql-hackers

From decibel
Subject Re: Stats for inheritance trees
Date
Msg-id 39AD2D76-7AF6-45F8-A545-5FF9D578398A@decibel.org
Whole thread Raw
In response to Re: Stats for inheritance trees  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Stats for inheritance trees  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Dec 29, 2009, at 6:29 PM, Tom Lane wrote:
> * when a tabstat message comes in, increment changes_since_analyze by
> the sum of t_tuples_inserted + t_tuples_updated + t_tuples_deleted;
>
> * when an analyze report message comes in, reset changes_since_analyze
> to zero.

If that's being added, could we extend the concept to also keep a reltuples_delta column (name suggestions welcome!)
thatis = reltuples_delta + t_tuples_inserted - t_tuples_deleted, and then set reltuples_delta back to 0 after an
analyze(or anything else that would reset reltuples)? That means you could use reltuples + reltuples_delta as a fairly
accuraterow count. 
--
Jim C. Nasby, Database Architect                   jim@nasby.net
512.569.9461 (cell)                         http://jim.nasby.net




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