Part I: Introduction to Active Session History

  • This presentation is the first of two aims to help you use the Active Session History (ASH) repository to investigate performance problems.  Oracle has produced many presentations that explain how ASH works, so this presentation provides only a very brief overview of how ASH works.  Instead, it looks at:
  • what information is collected by ASH and stored in the repository
  • where this data can be seen in Enterprise Manager and other delivered reports
  • the practicalities of how to directly query the ASH data to analyse and diagnose a range of performance and other problems.
  • the critical importance of application instrumentation
  • the value of a consolidated AWR/ASH repository
A video of this presentation (given to a NYOUG meeting) is available.