[Koha-devel] DB design (MARC structure)

[Paul POULAIN]

Hello all,

Nelsonville & me are trying to optimize queries.
I'm concluding we should modify a little the DB :
* marc_word has "tag", "subfield" and "word" fields.
* we are querying on /tag+subfield in ('200a','245f') and word like 
'tower%'/ . Such a query CANNOT be optimised by mySQL.
* so, an index on /(tag, subfield,word)/ is not used.
* I think we could highly optimize the search with a field called 
'tagsubfield', an index on /(tagsubfield,word)/. The search being 
/tagsubfield in ('200a','245f') and word like 'tower%'/.

Other searches (a search on "keyword", that does is done only on word, 
not on tag+subfield) will still be working fast, with index on (word)

Does this make sense ? Any comment ?
if yes, i'll do it (for friday).

-- 
Paul POULAIN
Consultant indépendant en logiciels libres
responsable francophone de koha (SIGB libre http://www.koha-fr.org)

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