September 17, 2013 archive

12c Move Datafiles Online

Prior to Oracle 12c, if you wanted to move a database’s file, you either had to shutdown the database, or take the datafile/tablespace offline. Here is an example of the steps you might take: ALTER TABLESPACE my_ts OFFLINE; !mv /old_dir/my_ts01.dbf /new_dir/my_ts01.dbf ALTER DATABASE RENAME FILE ‘/old_dir/my_ts01.dbf’ TO ‘/old_dir/my_ts01.dbf’; ALTER TABLESPACE my_ts ONLINE; Now in Oracle …

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12c Adaptive Plans

I’ve been meaning to write something up on Oracle 12c’s new Adaptive Plans. When I do have poorly performing SQL statements, it seems that the issue is often due to bad optimizer stats. Recalculate the stats and performance is improved. I like the new 12c feature of Adaptive Plans where the database engine will reformulate …

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