Oracle Database In-Memory Advisor



New!  Oracle Database In-Memory Advisor new version released.   Further details below.


Oracle Database In-Memory


Oracle Database 12.1.0.2 introduced Oracle Database In-Memory allowing a single database to efficiently support mixed analytic and transactional workloads. An Oracle Database configured with Database In-Memory delivers optimal performance for transactions while simultaneously supporting real-time analytics and reporting.

For complete details about Oracle Database In-Memory, see the Oracle Database In-Memory page on oracle.com.

Oracle Database In-Memory Advisor


Oracle Database In-Memory is designed to optimize analytical processing in the database. The In-Memory Advisor analyzes the analytical processing workload present in your database to determine an estimated benefit for the database as a whole if that analytical workload is optimized.

The In-Memory Advisor differentiates analytics processing from other database activity based upon SQL plan cardinality, Active Session History (ASH), use of parallel query, and other statistics.

The In-Memory Advisor estimates the In-Memory size of objects based upon statistics and heuristic compression factors.

The In-Memory Advisor estimates analytic processing performance improvement factors based upon the following:

  • Elimination of user I/O waits, cluster transfer waits, buffer cache latch waits, etc.
  • Certain query processing advantages related to specific compression types.
  • Decompression cost heuristics per specific compression types.
  • SQL plan selectivity, number of columns in the result set, etc.


The Advisor produces a recommendation report. The report lists a number of In-Memory sizes with estimated performance benefits, lists the objects which should be placed in the In-Memory column store for a given In-Memory size and the recommended compression factor for those objects.  It also produces a SQLPLUS script to modify the objects to place them In-Memory.

For information on obtaining the Advisor, please refer to My Oracle Support (MOS) note 1965343.1.

Updated In-Memory Advisor recently released.


The updates to the Advisor include:

  • A simplified and reformatted single page HTML report.
  • A new script to run the Advisor, imadvisor_recommendations.sql.   The script supports a number of additional uses of the Advisor.
  • Scalability enhancements.
  • Easier installation and deinstallation.
  • Additional views
  • Security improvements
  • Parameter improvements



Additional documentation:



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