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 […]