Re: [PERFORM] slow table updates

On Wed, 2003-07-23 at 10:47, Guthrie, Jeremy wrote:

> Have you checked the sizes of your indexes? You may need to rebuild them...
>
> Multiply the relpages colum by 8192.

So, what does this tell me? I'm guessing that you're implying that I
should expect 8192 keys per page, and that this therefore indicates the
sparseness of the key pages. Guessing that, I did:

rkh(at)csb=> SELECT c2.relname, c2.relpages, c2.relpages*8192 as "*8192",
43413476::real/(c2.relpages*8192) FROM pg_class c, pg_class c2, pg_index i
where c.oid = i.indrelid AND c2.oid = i.indexrelid and c2.relname~'^p2th|^papro'
ORDER BY c2.relname;

relname | relpages | *8192 | ?column?
---------------------------------+----------+------------+--------------------
p2thread_p2params_id | 122912 | 1006895104 | 0.0431161854174633
p2thread_pmodel_id | 123243 | 1009606656 | 0.0430003860830331
paprospect2_redundant_alignment | 229934 | 1883619328 | 0.0230479032332376

What do you make of 'em apples?

Thanks,
Reece

--
Reece Hart, Ph.D. rkh(at)gene(dot)com, http://www.gene.com/
Genentech, Inc. 650/225-6133 (voice), -5389 (fax)
Bioinformatics and Protein Engineering
1 DNA Way, MS-93 http://www.in-machina.com/~reece/
South San Francisco, CA 94080-4990 reece(at)in-machina(dot)com, GPG: 0x25EC91A0