SQL Tunning 2004-08-03 - By Wes Brooks
Hello expert,
Thank you very much for all of your reply.
But in my case, the 1 is variable. I tried the following but it complains that
SELECT TRUNC(SYSDATE)-22/86400 from dual;
TRUNC(SYS
-- ------
02-AUG-04 <--- Wrong date.
SELECT TRUNC(SYSDATE-22)/86400 from dual;
SELECT (TRUNC(SYSDATE)-22)/86400 from dual;
These two SQL statements gave the error:
ORA-00932 (See ORA-00932.ora-code.com): inconsistent datatypes
If I try this one, it works.
SELECT TRUNC(SYSDATE - 22), TO_DATE(TO_CHAR(TRUNC(SYSDATE-22+1), 'DD-MON-YYYY HH24:MI:SS '),
'DD-MON-YYYY HH24:MI:SS ') from dual;
Is there any way to improve this lengthly statement?
Thanks,
Wes
--- Edgar Chupit <edgar.chupit@(protected) > wrote:
> Hello Wes,
>
> WB > WHERE TRUNC(last_update_date) = TRUNC(SYSDATE - 1)
> WB > How to improve the performance? Do I need to create a new index field on the table with
> TRUNC(last_update_date)?
>
> You have several opportunities:
> a) you can rewrite your query to this:
> where last_update_date between trunc(sysdate)-1 and trunc(sysdate)-1/86400
> b) you can create function based index like:
> create index tt_idx on tt(trunc(last_update_date));
> c) you can add column to your table with values from trunc(last_update_date)
>
> What option to choose mostly depends on your requirements.
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