Oracle 19c Event mapping files

Here is the event mapping files for the new oracle 19c

As usual this include new added/removed events  :

Capture 01

19c on the left/18c on the right

As i showed in my previous blog post this event mapping files can be used in different use cases.Such as flame graph annotation :

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DML restart and tracked columns

Which columns are rely tracked by oracle to grantee write consistency and if needed trigger a DML restart when using the default statement-level consistency ?

Sometimes you may see strange ,unexpected behavior and write consistency bugs because not all the columns that are supposed to be tracked ,are really tracked !

Just check the following articles :

A bug from 2011 (still there in 18c) : http://db-blog.web.cern.ch/blog/franck-pachot/2018-09-oracle-write-consistency-bug-and-multi-thread-de-queuing

A Bug from 2006  (still there in 12.2) : http://blog.sqlora.com/en/merge-and-ora-30926-part-2-or-differences-in-write-consistency-between-update-and-merge/

So how to know it the columns that are supposed to be tracked really are ? I’m going only to treat UPDATE and MERGE statement here.

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