The profiles are a new (relatively) word in a database systems. Profiles of load on the file system, of a historical sessions behaviour, of SQL … Finally, the baseline or Oracle SQL Plan Management is a new (again relatively 🙂 ) instrument for working with explain plan of queries during the lifetime of the application that can manage the choose among explain plans and keep track of their evolutions.
There are a lot of technical surveys about it:
- Documentation http://docs.oracle.com/cd/E11882_01/server.112/e23633/preup.htm#UPGRD00232
- Maria Kolgan https://blogs.oracle.com/optimizer/entry/sql_plan_management_part_1_of_4_creating_sql_plan_baselines
- Johathan Lewis http://jonathanlewis.wordpress.com/2011/01/12/fake-baselines/
- NoCOUG 2012, №8 SQL Plan Management for Performance Testing
Let’s consider the principles of SPM on one simple example.