[Fwd: binary tree query]

From: Jodi Kanter <jkanter(at)virginia(dot)edu>
To: Postgres Admin List <pgsql-admin(at)postgresql(dot)org>
Subject: [Fwd: binary tree query]
Date: 2004-01-26 19:16:13
Message-ID: 4015677D.3090808@virginia.edu
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I have a biochemist telling me that this query below is a typical one
for crawling through a taxonomic tree and that this is how I should
represent some peptide information we have. Is there anyone on this list
familiar with such data? I am weak in the science department but this
query looks like it might not be the most efficient approach.
I have not been able to run an explain analyze yet as the database
structure and data are not in place yet. We are just in the planning
stages right now.

Any comments, suggestions, concerns, etc. would be much appreciated.
Would an experienced DBA recommend a different approach? Can anyone
offer some insight into the usefulness of INNER joins and the use of
BETWEEN? I am concernec about performance as well since I expect this
table to get large.

SELECT count(*)
FROM taxon_name
INNER JOIN taxon AS tax_b USING(taxon_id)
INNER JOIN taxon AS tax_v ON (tax_v.left_id BETWEEN
tax_b.left_id AND tax_b.right_id )
INNER JOIN annot ON (tax_v.taxon_id = annot.taxon_id)
INNER JOIN protein ON (protein.prot_id= annot.prot_id)
WHERE annot.pref = 1
AND taxon_name.taxon_id=207245
;

Thanks,
Jodi

--

/_______________________________
//Jodi L Kanter
BioInformatics Database Administrator
University of Virginia
(434) 924-2846
jkanter(at)virginia(dot)edu <mailto:jkanter(at)virginia(dot)edu>/

/ /

/ /

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