Re: Please suggest me on my table design (indexes!)
От | DaNieL..! |
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Тема | Re: Please suggest me on my table design (indexes!) |
Дата | |
Msg-id | fbeef6db-5bcc-4dd0-822d-84a0331c8e49@g1g2000yqh.googlegroups.com обсуждение исходный текст |
Ответ на | Please suggest me on my table design (indexes!) (DaNieL <daniele.pignedoli@gmail.com>) |
Ответы |
Re: Please suggest me on my table design (indexes!)
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Список | pgsql-general |
The `problem` is that i dont know if having so many indexes will raise problems as the data dimension grown. And i am not even sure that this design is truly reliable; For example, if i would to know how many employees have every company, i'll have to run that query: ----- EXPLAIN ANALYZE SELECT c.id, c.company_name, count(e.id) AS num_employee FROM contact AS c LEFT JOIN contact AS e ON (c.id = e.id_company) WHERE c.tipo = 'company' GROUP BY c.id, c.company_name ----- That seem to be not very efficient: http://explain.depesz.com/s/Q0m (I loaded some test data from http://www.generatedata.com/#generator, so now i have 23893 rows in the table.. oh, i added a index on the 'kind' (tipo) column too) On 23 Giu, 13:47, gryz...@gmail.com (Grzegorz Jaśkiewicz) wrote: > it looks ok on explain, that is - the cost isn't too high. > So what's the problem ? > > -- > Sent via pgsql-general mailing list (pgsql-gene...@postgresql.org) > To make changes to your subscription:http://www.postgresql.org/mailpref/pgsql-general
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