Re: Basic question about indexes/explain
От | Mario Weilguni |
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Тема | Re: Basic question about indexes/explain |
Дата | |
Msg-id | 200210261340.06876.mweilguni@sime.com обсуждение исходный текст |
Ответ на | Basic question about indexes/explain (Terry Yapt <pgsql@technovell.com>) |
Ответы |
Re: Basic question about indexes/explain
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Список | pgsql-performance |
Am Samstag, 26. Oktober 2002 12:27 schrieb Terry Yapt: > Hi all, > snip > I have a basic doubt about indexes... in the next example: > But if we have an index with the two colums I am using in the WHERE clause, > why is the planner using seq scan ? (Or perhaps it is because too few rows > in the table ?).... First of all, you did not analyze your table (at least you did not mention you did). And an index is never a win for sucha small table. I think the planner is fine here to select a seq scan, because your whole table is only 1 database page,so it would be no win to check the index here. Everything is explained in the manual, check http://developer.postgresql.org/docs/postgres/indexes.html regards, mario weilguni
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