DBA SGA Active Session History

Categories: Diagnostic Pack, Enginatics, Toolkit - DBA
Repository: Github Columns: Sample Time, Inst Id, Sid Serial#, User Name, Responsibility, Module Type, Module Name, Ui Type, Code, Code Line# ...
Active session history from the SGA.

Parameter 'Blocked Sessions only' allows a blocking screnario root cause analysis, e.g. by doing a pivot in Excel (see example in the online library).
The link to blocking sessions is deliberately nonunique without jointing to sample_id to increase the chance to fetch the blocking session's additional information such as module, action and client_id.
In some cases, such as row lock scenarios, the blocking session is idle and does not show up in the ASH then.
For scenarios where the blocking sessions are active and part of the ASH, Tanel Poder has a treewalk ash_wait_chains.sql, showing the whole chain of ASH records linked by a unique join, including the sample_id: