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Overview

The user can monitor performance degradation due to transaction lock.

 

Version

  • This document is written based on Altibase HDB version 6.3.1.
  • Both ALTIBASE HDB 5 and ALTIBASE HDB 6 can be used, but some monitoring items may cause a result error.
  • For more information and updates, please leave a request at http://support.altibase.com/en/ or in the comment section on this page.

 

How to monitor

First of all, there are two performance views for the lock information of Altibase.

These are v$loc and v$lock_statement.

First, in v$lock, the user can inquire what type of lock is applied to a table. In the case of a select statement, IX_LOCK will be locked in case of changes such as IS_LOCK, insert, update, delete, etc.

By joining this view and the system_.sys_tables_ meta table, the user can check table name and lock information.

In addition, the user can also check which queries are holding the lock with v$lock_statement.

The user can check the query holding the lock by joining the trans_id of v$lock and the tx_id of v$lock_statement.

The user can check the session ID of the query currently holding the lock by using multiple joins.

desc v$lock;

With v$lock_statement;, check which columns are existed.

the session can also be killed with the session_id obtained in this wa.

The above command can be executed by entering sysdba.

++ Lock wait query

++ Look up based on v$lock_wait view, such as tx_id waiting, lock grant time, related redo logfile location, etc.

++ Check the client_pid and session_id holding the lock

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