FreeLists / oracle-l / Re: SQL Tunning

["Carel-Jan Engel" <cjpengel.dbalert@xxxxxxxxx>]

You can also create a function based index on TRUNC(last_update_date), but
w/o any changes to your tables and/or indexes rephrasing the query to
WHERE last_update_date BETWEEN TRUNC(SYSDATE - 1) AND  TRUNC(SYSDATE -
1/86400)
will make an index-range scan possible. The 1/86400 is to subtract 1
second of the SYSDATE, to prevent including the 0:00:00 updates of today.

Regards, Carel-Jan

===
If you think education is expensive, try ignorance. (Derek Bok)
===



> Hello expert,
>
> I have a table with 40 millions records and the last update date is
> indexed.  But when we use the
> following where clause, it takes forever to run the report.
>
>    WHERE TRUNC(last_update_date) = TRUNC(SYSDATE - 1)
>
> How to improve the performance?  Do I need to create a new index field on
> the table with TRUNC(last_update_date)?
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