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: Sqlplus Displays Last Login Time For Non – Sys Users

12c database has introduced a pretty nifty Security feature which allows you to check last login time for non-sys user. e.g If I connect to scott user as below, it displays that I last logged in at Mon Jul 22 2013 09:06:07 +00:00. Time is displayed in local format (UTC in this case) [oracle@oradbdev01]~% sqlplus scott/oracle…

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…

Openfiler on Virtualbox and 12c Oracle Flex ASM

Last week Oracle released 12c database and Oracle blogosphere is bustling with lot of people posting details about new versions and setup. I too decided to take plunge and setup my own RAC cluster. I had 4 machines with me but no shared storage 🙁 Long back I had done one installation using openfiler (Followed…