Blocking View for Teradata Database - Teradata Workload Management - 16.20

Teradata® Viewpoint User Guide

prodname
Teradata Viewpoint
Teradata Workload Management
vrm_release
16.20
category
User Guide
featnum
B035-2206-107K

When a query is holding locks that are blocking other queries from completing, use the Blocking view to gauge the impact of this blocking. By analyzing the number and type of queries blocked by this query, you can decide the best course of action to resolve the issue.

This information in this view is read-only. The view is available only when the selected query is blocking other queries and when connected to Teradata Database 15.0 and later.

Blocking Information Description
Blocking Type Indicates the significance of the blocker. Available values are:
  • Root Cause - Sessions that are not blocked, but are causing other sessions to be blocked
  • Granted - Sessions that are blocked and are blocking other sessions because they have been granted a lock
  • Waiting - Sessions that are blocked and are ahead of other blocked sessions in the queue
Blocking Count Total number of sessions that are either directly or indirectly blocked by this session
Blocking Time Amount of elapsed time that this session has been blocking other sessions, displayed as
  • d +hh :mm :ss
Blocking Impact Blocked time summed together of each session that is either directly or indirectly blocked by this session, displayed as
  • d +hh :mm :ss
Blocking Locks A comma-separated list of the locks that are responsible for the blocking, for example:

Granted write lock on table databaseName.tableName, Waiting on write lock on rowhash databaseName.tableName

The information displays in the following order:
  1. Status of the lock causing the block (Waiting or Granted)
  2. Mode (severity) of the lock involved in causing a block (exclusive, write, read, or access)
  3. Type of object whose lock is causing the session described by the associated row to be blocked (database, table, row hash, table partition range, row hash partition range, row hash partition, and row key range)
  4. Name of the database object over which a lock conflict is preventing the session from being granted a lock
  5. Name of the table object over which a lock conflict is preventing the session from being granted a lock
Session ID Unique session identifier of the query that is blocking
Blocked Time How long the query has been blocked, displayed as
  • d +hh :mm :ss
Username Name of the user that is running the query that holds the lock
Workload Name of the workload where the query is actively running
Query Band String of key/value pairs of the query band for the session or transaction