Re: How to find greatest record before known values fast
От | Andrus |
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Тема | Re: How to find greatest record before known values fast |
Дата | |
Msg-id | C2F1B84DC3F14AFD96F3132C78991CEB@dell2 обсуждение исходный текст |
Ответ на | Re: How to find greatest record before known values fast (Jim Nasby <Jim.Nasby@BlueTreble.com>) |
Ответы |
Re: How to find greatest record before known values fast
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Список | pgsql-general |
Hi! >So kellaaeg is a time? Your best bet here would be to create an index that >is an actual timestamp comprised of both >kuupaev and kellaaeg. You could >do this with to_timestamp by concatinating both fields together, or it may >be easier to replace the space in kellaaeg with a colon and cast it to >time, then add the two: > kuupaev + replace( kellaaeg, ' ', ':' )::time >I know you can't alter the table, but can you create a view on top of the >table? If you did that, you could have a real >timestamp field in the view >that is calculated from kuupaev and kellaaeg and you can create a >functional index that >uses the same calculation. That would be the easiest >way to use this. Thank you. I solved this by creating composite index on 3 columns and re-writing query as Tom recommended. It looks like Tom's recommendation is simpler for me. Andrus.
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