Peformance Tuning

ORA-12801: error signaled in parallel query + ORA-04031: unable to allocate 65560 bytes of shared memory (“large pool”)

Yesterday I got request from one of the user saying his job failed giving following error: Severity Timestamp Node Thread Message Code Message ERROR 2014/10/24 02:59:32 PM node-uat-informatika READER_1_1_1 RR_4035 SQL Error [ ORA-12801: error signaled in parallel query server P178, instance rmb-uat-db-gik1:DBGIK1 (1) ORA-12853: insufficient memory for PX buffers: […]

Multiple failed login attempts can cause high number of row cache lock wait events in 11g

From Oracle 11g, there is a new security enhancement that has potential of creating huge performance issues due to¬†failed login attempts through multiple sessions. Yesterday we faced this¬†issue on production database, all application users were complaining about slow performance especially while making new connections with database. After having quick check […]