Re: Possible to improve query plan?
| От | Jayadevan M |
|---|---|
| Тема | Re: Possible to improve query plan? |
| Дата | |
| Msg-id | OFCF071F4A.48152E2C-ON6525781B.002EEEE4-6525781B.002FFBBE@ibsplc.com обсуждение исходный текст |
| Ответ на | Possible to improve query plan? (Jeremy Palmer <JPalmer@linz.govt.nz>) |
| Список | pgsql-performance |
Hello,
>
> The distribution of the data is that all but 120,000 rows have null
> values in the _revision_expired column.
>
A shot in the dark - will a partial index on the above column help?
http://www.postgresql.org/docs/current/interactive/indexes-partial.html
http://en.wikipedia.org/wiki/Partial_index
One link with discussion about it...
http://www.devheads.net/database/postgresql/general/when-can-postgresql-use-partial-not-null-index-seems-depend-size-clause-even-enable-seqscan.htm
Regards,
Jayadevan
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>
> The distribution of the data is that all but 120,000 rows have null
> values in the _revision_expired column.
>
A shot in the dark - will a partial index on the above column help?
http://www.postgresql.org/docs/current/interactive/indexes-partial.html
http://en.wikipedia.org/wiki/Partial_index
One link with discussion about it...
http://www.devheads.net/database/postgresql/general/when-can-postgresql-use-partial-not-null-index-seems-depend-size-clause-even-enable-seqscan.htm
Regards,
Jayadevan
DISCLAIMER:
"The information in this e-mail and any attachment is intended only for the person to whom it is addressed and may contain confidential and/or privileged material. If you have received this e-mail in error, kindly contact the sender and destroy all copies of the original communication. IBS makes no warranty, express or implied, nor guarantees the accuracy, adequacy or completeness of the information contained in this email or any attachment and is not liable for any errors, defects, omissions, viruses or for resultant loss or damage, if any, direct or indirect."
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