Db Log Queue Test

The log queue is the main memory area, in which redo log entries from the transactions are stored. The Db Log Queue test monitors the usage of the log queue.

Target of the test : A MaxDB server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for every log queue on the MaxDB server being monitored.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.


The host name of the server for which the test is to be configured.


The port number to which the server is listening.


The test connects to a database on MaxDB and extracts performance statistics from the system tables in the database. Therefore, provide the name of a database in the DatabaseName text box.


Since users with the SYSDBA privilege alone are allowed access to system tables, specify the name of such a user against Username.


Provide the Password that corresponds to the specified Username.

Confirm Password

Confirm the password by retyping it here.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Queue max used

Indicates the maximum number of transactions written to the log queue.



Log entries inserted

Indicates the number of log entries inserted into the queue in the last measurement period.



Queue overflow

Indicates the number of wait situations that arose due to log queue overflows in the last measurement period.


If the log queue becomes full before log pages are written to the log area, then a log queue overflow occurs. If the value of this measure keeps increasing, you might want to consider altering the log queue size by resetting the LOG_IO_QUEUE parameter.

Group commits

Indicates the number of log pages whose writing was waited for by more than one transaction, in the last measurement period.



Log queue transactions

Indicates the number of transactions waiting to write in the log queue in the last measurement period.



Max waits per page

Indicates the maximum number of transactions that simultaneously waited for the same page to be written.


A high value of this measure could cause undue delays in transaction execution.

Physical write rate

Indicates the rate at which log pages were written to the log area.