Oracle Scratchpad

February 19, 2022

Infrastructure Catalogue

Filed under: Oracle — Jonathan Lewis @ 10:41 am GMT Feb 19,2022

This is a list of articles I’ve written that get a little heavily into technical details and won’t necessarily be very helpful to the typical DBA or developer. Each entry has a date stamp and a short note of the contents. The articles are generally listed most-recent first.

  • Dumping redo (Sept 2022): a convenient method for minimising the redo you need to dump when testing a feature.
  • Shrinking Indexes (Sept 2022): A lesson in comparing workloads – in this case index coalese vs. shrink space (with or without compact).
  • Drop Partition (Aug 2022): the mechanics and cost of deferred global index maintenance
  • ORA-00054 pt.1 (July 2022): Trouble-shooting with errorstack and ksq trace
  • Why “lag() ignore nulls” is slow (May 2022): and how to work around the problem in some cases.
  • dbms_redefinition defect (May 2022): using copy_table_dependencies() can produce metadata inconsistencies.
  • Long v$ definitions (Mar 2022): Some definitions in v$fixed_view_definition are too long for the view. A workaround.
  • X$ row sizes (Mar 2022): Simple script to get some clue about rows in x$ structures
  • V$ cascade (Mar 2022): Why does is v$ a synonym for v_$ which is a view on v$
  • Digging into x$ (Mar 2022): preliminary investigation of x$ information
  • Session Count issue (Mar 2022): v$session, v$resource_limit and v$sysmetric don’t agree – digging in to x$
  • Data Defaults (Feb 2021): a quirky little detail about how column defaults can be stored (and a point in favour of “commas at the ends of lines”).
  • Pivot Cosmetics (Feb 2021): a minor change in the SQL*Plus output for a pivot that may require format updates in your code.
  • Supplemental logging mess (Jan 2021): you need to be a little careful when you add supplemental logging clauses to a table.
  • Check Constraints (Jan 2021): an odd difference in locking and waiting between disabling and enabling constraints.
  • Naming side-effects (Dec 2020): How an upgrade that allows longer object names could break existing code.
  • Dates and formats (Dec 2020): It’s important to use date datatypes, and check for type-conversion threats.
  • Java Names upgrade (Dec 2020): how an upgrade from 12c to 19c caused an error in “home-grown” auditing.
  • Row Sizes – pt.3 (Nov 2020): a little hackery to report the relative frequency of nulls in each column of a table.
    • Row sizes – pt2 (Oct 2012): a little hackery to generate code to show the patterns of Nulls in the rows of a table.
    • Row sizes – pt1 (Sep 2012): a little hacker to generate a “histogram” showing the distribution of row sizes in a table.
  • Querying v$session (Oct 2019): a performance threat for large systems
  • What’s my SID (Oct 2019): several ways of getting the SID (and some for the serial#)
  • Dumping redo (June 2019): includes examples of how to be selective in dumping (online and archived) redo log records.
  • Redo Op Codes (July 2017): my personal reference for translating redo op codes.
  • Unpivot mechanics (June 2017): what does Oracle do internally to handle an unpivot?
  • Optimising statspack (Oct 2016): some data dictionary / internal queries really do need good stats to avoid performance disasters.
  • v$lock efficiency (May 2013): the benefit of collecting stats on individual x$ structures
  • Hint error (Feb 2012): why is v$sql_shared_memory returning no data?
  • Real-time Block Recovery (Dec 2010): How Oracle may handle blocks in the buffer cache that appear to have been corrupted
  • Lock Modes (June 2010): my personal reference for translating numeric lock modes.
  • PGA Memory (June 2009): checking process memory and process memory detail.
  • Oracle Pipes (Jan 2009): What’s currently inside a pipe created by dbms_pipe.

1 Comment »

  1. […] Infrastructure (geek stuff) catalogue […]

    Pingback by Catalog Catalogue | Oracle Scratchpad — February 19, 2022 @ 10:42 am GMT Feb 19,2022 | Reply


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