LGWR terminating instance due to error 338

Recently we came across a issue where our DB crashed with ORA-00338 error . Errors in file /oracle/diag/rdbms/orcl11g/orc11g/trace/orc11g_lgwr_24118.trc: ORA-00338: log 2 of thread 1 is more recent than control file ORA-00312: online log 2 thread 1: ‘/oracle/oradata/orcl11g/redo02.log’ LGWR (ospid: 24118): terminating the instance due to error 338 DB couldn’t be restarted as it gave same errors…

MGMTDB: Grid Infrastructure Management Repository

MGMTDB is new database instance which is used for storing Cluster Health Monitor (CHM) data. In 11g this was being stored in berkley database but starting Oracle database 12c it is configured as  Oracle Database Instance. In 11g, .bdb files were stored in $GRID_HOME/crf/db/hostname and used to take up lot of space (>100G) due to bug…

12c: Exporting Database Views as Tables

Starting Oracle Database 12c, you can export view to be imported as a table. There is no need to individually export each table, Data Pump will dump a table with the same columns as the view and with row data fetched from the view. It also exports objects dependent on the view, such as grants…

12c:Limiting PGA with pga_aggregate_limit

This is a interesting feature for Oracle DBA’s. Till now there has been no way of limiting total PGA being used by oracle instance. _pga_max_size (hidden parameter) could be used to limit per process memory. SGA_TARGET used to be hard limit for Oracle SGA but PGA_AGGREGATE_TARGET only controlled allocation of PGA memory to each process via oracle…

12c:Specifying lock timeout for finish_redef_table

Oracle 12c database has introduced enhancement to DBMS_REDEFINITION for specifying a a lock timeout (in seconds) which will allow FINISH_REDEF_TABLE to acquire an exclusive lock for swapping the source and interim tables.If timeout expires, then operation exits. This will help to   avoid cancellation by user or indefinite wait. This does not put our session in queue…