Skip to Content
0
Former Member
Apr 21, 2009 at 06:40 AM

Reduce number of disk reads for a select statement..

21 Views

Hi Experts,

I had a Select statement like this ,

SELECT approval_agent

FROM zmep_sc_app_hist

INTO CORRESPONDING FIELDS OF TABLE t_tab_approval_agent

WHERE item_guid EQ us_sc_i_guid

AND appr_description NE c_con_valid.

which is causing high number disk reads in the Production system,

so i got a suggesion that,if we remove the Negative checks like " NE" in select statemant

and removing the "CORRESPONDING FILEDS ".... will improve performance..

Does this reduce the number of disk reads..?

please suggest if I change the above select like this does it improve performance..or decrease the disk reads ..

SELECT approval_agent

FROM zmep_sc_app_hist

INTO CORRESPONDING FIELDS OF TABLE t_tab_approval_agent

WHERE item_guid EQ us_sc_i_guid

Delete zmep_sc_app_hist where appr_description NE c_con_valid.

Regards

sivaram