Infrastructure Catalogue

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.

• 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$sysmetric don’t agree – digging in to x$
• Querying v$session (Oct 2019): a performance threat for large systems
• What’s my SID (Oct 2019): several ways of getting the SID (and some for the serial#)
• Dumping redo (June 2019): includes examples of how to be selective in dumping (online and archived) redo log records.
• Redo Op Codes (July 2017): my personal reference for translating redo op codes.
• v$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?
• Lock Modes (June 2010): my personal reference for translating numeric lock modes.
• Oracle Pipes (Jan 2009): What’s currently inside a pipe created by dbms_pipe.