Hi Thanks a lot and found I can not delete all histogram as you have mentioned. Now I know only few SQL have the multiple PLAN_HASH_VALUE. I think I have remove only related columns histogram. Could you please confirm and the method if you already done before. select hash_value,plan_hash_value,count(*) from v$sql where sql_text like '%:"SYS_B_0"%' group by hash_value,plan_hash_value; HASH_VALUE PLAN_HASH_VALUE COUNT(*) 3722612061 3351193255 113 1983846182 3351193255 112 2831213151 2975737795 21 Regards Mudhalvan M.M ________________________________ From: Tanel Poder [mailto:tanel@xxxxxxxxxx] Sent: Thursday, March 18, 2010 9:44 AM To: Mudhalvan Moovarkku Cc: Oracle-L@xxxxxxxxxxxxx Subject: Re: Library Cache and Share wait on Latch - Version Count Huge After setting method_opt to REPEAT you will also need to manually drop all the histograms, as they have been already created for you. However I don't know your application/data, maybe you do need some histograms somewhere, so you need to review the histograms you have yourself and decide whether it's ok to get rid of them. If it's purely an OLTP system with bind variables used everywhere, its probably ok to get rid of all histograms as histograms and bind variables are a deadly combination anyway - for stable performance. -- Tanel Poder http://tech.e2sn.com On Thu, Mar 18, 2010 at 8:38 AM, Mudhalvan Moovarkku <moovarkku.mudhalvan@xxxxxxxxxxxxxxxx> wrote: Hi Tanel Thanks for your suggestion. I am very sorry due the bad application we will not be able to change SIMILAR to FORCE. So I have to clear the Histograms I this METHOD_OPT from AUTO to REPEAT will help me. I will check on the dbms_stats.get_param and change it to REPEAT if no impact.