Re: bitmask index
От | Greg Smith |
---|---|
Тема | Re: bitmask index |
Дата | |
Msg-id | 4E0261C1.8000807@2ndQuadrant.com обсуждение исходный текст |
Ответ на | bitmask index (Marcus Engene <mengpg2@engene.se>) |
Ответы |
Re: bitmask index
Re: bitmask index |
Список | pgsql-performance |
On 06/22/2011 05:27 PM, Marcus Engene wrote: > I have some tables with bitmask integers. Set bits are the interesting > ones. Usually they are sparse. If it's sparse, create a partial index that just includes rows where the bit is set: http://www.postgresql.org/docs/current/static/indexes-partial.html You need to be careful the query uses the exact syntax as the one that created the index for it to be used. But if you do that, it should be able to pull the rows that match out quickly. -- Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.us "PostgreSQL 9.0 High Performance": http://www.2ndQuadrant.com/books
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