Oracle Scratchpad

January 27, 2022

Statistics catalogue

Filed under: Oracle — Jonathan Lewis @ 6:16 pm GMT Jan 27,2022

This is a list of all articles I’ve written that talk about statistics, with a date stamp and short note of the contents. I have also created a couple of sub-catalogues around major topics:

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

  • 19c – better stats (April 2022): Oracle now uses approx_count_distinct() on the whole index in dbms_stats.gather_index_stats().
  • system_stats() hint (Jan 2022): notes on a hint that allows you to set the “noworkload” system statistics in a hint on Exadata.
  • Optimizer Tip (Sept 2021): reprint of a note for IOUG 2015 on column groups and the table_cached_blocks preference
  • Stats preferences (Aug 2021): a simple query to report all the system and table preferences, default or explicitly set
  • Using the num_index_keys() hint (Nov 2018): controlling the split between access and filter predicates used in the index for complex in-lists.
  • Reporting times of stats operations (Sept 2018): dbms_stats functions to report details of stats gathering operations.
  • table_cached_blocks defect (July 2018): A table preference about indexes, but it isn’t used during create or rebuild of index.
    • table_cached_blocks and RAC (Nov 2015): if you set the table preference to adjust the index clustering_factor, should you allow for the effects of RAC?
    • table_cached_blocks (May 2013): At last, a “legal” way to adjust the clustering_factor to a realistic value.
  • Optimising statspack (Oct 2016): selective stats collection for data dictionary / internal queries.
  • v$lock efficiency (May 2013): the benefit of collecting stats on individual x$ structures
  • Minimum Stats (Sept 2012): auto_sample_size on an index tends to mean 1,140 blocks

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1 Comment »

  1. […] Statistics catalogue […]

    Pingback by Catalog Catalogue | Oracle Scratchpad — January 27, 2022 @ 6:18 pm GMT Jan 27,2022 | Reply


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