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How to Determine the SQL Statements Executed by a Blocking Session in the Past Using Active Session History (ASH) Report (Doc ID 2406026.1)

Last updated on APRIL 05, 2021

Applies to:

Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Oracle Database Backup Service - Version N/A and later
Information in this document applies to any platform.

Goal

The Active Session History (ASH) report indicates that one session ID was acting as a blocker during most of the time period.  However, the Top Blocking Sessions Section of the report does not indicate what that session was doing during the described time period.

For example, in this ASH report you see that session ID 1419 was causing a lot of other sessions to wait on the shared pool latch:

Top Blocking Sessions

Blocking Sid (Inst) % Activity Event Caused % Event User Program # Samples Active XIDs

1419,22993( 1) 23.26 latch: shared pool 23.26 USI Cal@cja (TNS V1-V3) 586/600 [ 98%] 2
24450, 2949( 1) 5.46 library cache: mutex X 5.43USI Cal@cja (TNS V1-V3) 566/600 [ 94%] 2
12700, 837( 1) 1.71 latch: shared pool 1.71 USI Cal@cja (TNS V1-V3) 581/600 [ 97%] 2

Knowing more about the activities of session 1419 may provide clues as to why other sessions were unable to obtain the shared pool latch.  How do you determine what SQL statements that session was executing?

 

Solution

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In this Document
Goal
Solution
References

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