Thank you Tanel. Setting "_awr_disabled_flush_tables" parameter is nice temporary solution to avoid getting annoying trace files and core dumps. I must remember this parameter. As I can see this parameter solves many collection or performance problems. I think it's pretty safe to set this parameter. btw What is "WRH$_MEM_DYNAMIC_COMP"? Shouldn't be enough for this particular problem just to execute: alter system set "_awr_disabled_flush_tables"='WRH$_MUTEX_SLEEP'; (haven't executed this yet) Thanks for answer. Regards, Marko On Sun, Dec 9, 2012 at 5:08 PM, Tanel Poder <tanel@xxxxxxxxxxxxxx> wrote: > Starting from 10.2 you can disable the insertion data into individual AWR > tables using *_awr_disabled_flush_tables* parameter. > > You need to provide (comma separated) AWR table name(s) as the value, like: > > alter system set > "_awr_disabled_flush_tables"='WRH$_MUTEX_SLEEP,WRH$_MEM_DYNAMIC_COMP'; > > (all the names you can use are listed in *x$kewrtb* fixed table. > > There's more interesting stuff in this metalink note: Troubleshooting: AWR > Snapshot Collection issues [ID 1301503.1] > > -- > Tanel Poder > Blog - http://blog.tanelpoder.com > App - http://voic.ee > > > > On Sun, Dec 9, 2012 at 11:38 AM, Marko Sutic <marko.sutic@xxxxxxxxx>wrote: > >> Hi all, >> with every AWR snapshot I get "ORA-00001: unique constraint >> (SYS.WRH$_MUTEX_SLEEP_PK) violated" which generates trace file and core >> dump. >> >> I' aware that this error is not dangerous but in 3 days I have 3.5G of >> trace files with snapshot taking every 15 mins. >> Tracing ORA-00001 errors is not enabled by default but I have to enable >> this because I want to trace ORA-00001 errors for prod application. >> >> I've dropped all historical snapshots using >> DBMS_WORKLOAD_REPOSITORY.DROP_SNAPSHOT_RANGE but this error again appears >> with every new AWR snapshot. >> >> >> There is Metalink document related to this error: >> ORA-00001: Unique Constraint (SYS.WRH$_MUTEX_SLEEP_PK) Violated [ID >> 1498713.1] >> >> >> > -- *----* *Marko Sutic* My LinkedIn Profile <http://hr.linkedin.com/in/markosutic> -- //www.freelists.org/webpage/oracle-l