Is it possible to create row-wise indexable condition for special case...

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От Maxim Boguk
Тема Is it possible to create row-wise indexable condition for special case...
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Msg-id CAK-MWwQ-Pn9NvLZZSpmUxjbP-3HeEH2T4+6FAdX5h1bX7VXpmw@mail.gmail.com
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Ответы Re: Is it possible to create row-wise indexable condition for special case...  (François Beausoleil <francois@teksol.info>)
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Hi,

I know that for condition like   ((field1>value1) or (field1=value1 and field2>value2))  I could built index on (field1, field2) and use indexable condition like   (field1, field2) > (value1, value2).

However, I have very tricky query which requires an indexable condition like  (field1>value1) or (field1=value1 and field2<value2).
I guess that I could use index definition like ON(field1, field2 DESC) however,  I can not build query condition which would use that index effectively.

Is it possible and my mind just went black on simple task?

PS: field2 is varchar type so I couldn't using the negative values trick
build index ON(field1, (-field2))
and write something like WHERE (field1, -field2) > (value1, -value2).

--
Maxim Boguk
Senior Postgresql DBA
http://www.postgresql-consulting.ru/

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