Re: Index of a table is not used (in any case)
От | Doug McNaught |
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Тема | Re: Index of a table is not used (in any case) |
Дата | |
Msg-id | m3y9m2h5mg.fsf@belphigor.mcnaught.org обсуждение исходный текст |
Ответ на | Index of a table is not used (in any case) (Reiner Dassing <dassing@wettzell.ifag.de>) |
Список | pgsql-sql |
Reiner Dassing <dassing@wettzell.ifag.de> writes: > I would like to mention first, that I will use the [SQL] list for my > answers, > regarding the notice of Josh Berkus. > > Q: "did you use VACUUM ANALYZE"? > A: This table was a test bed, just using INSERTS without ANY deletes or > updates You still need to run VACUUM ANALYZE. The ANALYZE part measures the statistics of your data, which the planner needs in order to make decision. > Am afraid, that the real answer is not mentioned: > Why is the index used in the SELECT: > select * from wetter order by epoche desc; > > > select * from wetter where epoche between '1970-01-01' and '1980-01-01' > order by epoche asc; If you EXPLAIN output for these queries, someone can probably help you. -Doug -- Let us cross over the river, and rest under the shade of the trees. --T. J. Jackson, 1863
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