My Oracle Support Banner

Facing Many Blocking Session For Parallel Queries After 11gR2 Upgrade. (Doc ID 1968169.1)

Last updated on FEBRUARY 27, 2019

Applies to:

Oracle Database - Enterprise Edition - Version 11.2.0.3 and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud 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
Information in this document applies to any platform.

Symptoms

When a threshold is set for 'DBMS_SERVER_ALERT.BLOCKED_USERS' using server alert functionality, alerts are generated in 11.2 and up for situations where
a parallel query coordinator is waiting on parallel slaves to return results. These waits are cleared automatically.

You will see messages similar to 'Session XXXX is blocking 0 other sessions'.

Changes

 Upgrade to 11.2.

Cause

To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!


In this Document
Symptoms
Changes
Cause
Solution
References


My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.