Oracle Scratchpad

January 28, 2022

Performance catalogue

Filed under: Oracle — Jonathan Lewis @ 4:52 pm GMT Jan 28,2022

This is a list of articles that discuss design ideas that can have a big impact on performance. Each entry has a date stamp and a short note of the contents. The articles are generally listed most-recent first.

I am currently working backwards through my entire blog adding articles to catalogues as I go, so any individual catalogue may grow very slowly.

On the this blog

  • Analytic Sorts (Nov 2022): Investigating a performance issue and finding a hole in a gap in an internal optimisation
  • Hash Joins and functions (July 2022): how a trim() function in a hash join predicate used 1,800 seconds of CPU.
  • Control File Waits (Jan 2022): Investigating where time can be lost on I/O with basicfile Lobs.
  • Hacking with MVs (Dec 2021): reprint of a very old article on using materialized views to address performance issues with 3rd party systems
  • Thoughts on “best practice”(Dec 2021): to join, use scalar subqueries, or other?
  • Statistics_Level (Nov 2021): a quick check on what diagnostic statistics are active
  • Sequence accelerator (Aug 2021): it’s important to think about the sequence cache size for most versions of Oracle, but an enhancement in 21c allows you to forget about it (almost).
  • A little tweak in 19c (July 2021): the optimizer adding an “is not nulll” predicate that changes the cost of an execution path.
  • Troubleshooting (August 2019): A generic strategy and specific example of how to re-engineer certain classes of query
  • Unpivot mechanics (June 2017): what does Oracle do internally to handle an unpivot?

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1 Comment »

  1. […] Performance catalogue […]

    Pingback by Catalog Catalogue | Oracle Scratchpad — January 28, 2022 @ 5:30 pm GMT Jan 28,2022 | Reply


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