UKOUG2020

Thursday, November 05, 2020

Oracle 19c: Real-Time Statistics & High-Frequency Statistics Collection

The video of this recent presentation, given as a part of the Oracle Groundbreakers EMEA Tour 2020, is now available.
Keeping object statistics up to date is critical to Oracle database performance and stability. Both of these features aim to address the challenge of using data that has been significantly updated before the statistics maintenance window has run again. The features are only available on engineered systems, and so certainly are targetted at the autonomous database.
  • Real-time Statistics augment existing statistics. However, they are not quite as real-time as the name suggests. To keep their implementation lightweight they use the table monitoring mechanism, this limits the information that can be collected.
  • High-Frequency Automatic Optimizer Statistics Collection is effectively a never-ending statistics maintenance window. As your data and statistics change, so there are opportunities for SQL execution plans, and therefore application performance to change. DBAs and developers need to be aware of the implications.

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