Re: Index Management
От | Steve Brett |
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Тема | Re: Index Management |
Дата | |
Msg-id | a3e5n7$1mhr$1@news.tht.net обсуждение исходный текст |
Ответ на | Index Management (pocm@rnl.ist.utl.pt (Paulo J. Matos)) |
Список | pgsql-sql |
AFAIK the indeces are chosen by the query optimiser and used whenever they are needed. sometimes if the optimiser decides it may not use an index if there are a small number of rows in the table and sequential scan would be as fast. a general rule of thumb i use is that indexes are placed on tables if i have a query that uses that attribute in the where clause. Steve "Paulo J. Matos" <pocm@rnl.ist.utl.pt> wrote in message news:87d6zr1fdm.fsf@localhost.localdomain... > Hi all, > > I've been creating indeces for my tables but I'm a bit lost > now. I'd like to know how indeces are managed? Are them > autommaticly chosen for a particular query? We choose the good > ones (maybe through a sql command)? > If I create 10 indeces and then I make some queries, how will > postgres manage the indeces and how to work through the queries? > > Best regards, > > -- > Paulo J. Matos : pocm(_at_)rnl.ist.utl.pt > Instituto Superior Tecnico - Lisbon > Software & Computer Engineering - A.I. > - > http://www.rnl.ist.utl.pt/~pocm > --- > Yes, God had a deadline... > So, He wrote it all in Lisp! > > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly
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