Informix Unused Indexes Test

One of the balancing acts of Informix server is the use of indexes.  Too few indexes can cause scans to occur which hurts performance and too many indexes causes overhead for index maintenance during data updates and also a bloated database. Administrators hence need to continuously track which indexes are used and how they are used. Unused indexes in particular can have a negative impact on performance. This is because when the underlying table data is modified, the index may need to be updated also. This takes additional time and can even increase the probability of blocking. To avoid this, administrators need to rapidly isolate the unused indexes and drop them. The Informix Unused Indexes test facilitates this. Using this test, administrators can quickly determine the number of unused indexes in each database, and also understand how badly that index impacts database performance.

Target of the test : A Informix Dynamic Server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for each database on the Informix server monitored.

Configurable parameters for the test
Parameters Description

Test Period

This indicates how often should the test be executed.

Host

The IP address of the Informix Dynamic server.

Port

The port number at which the specified host listens to.

Instance

The Informix server instance being monitored.

User

A valid Informix user name.

Password

The password corresponding to the above user.

Confirm Password

Confirm the Password by retyping it here.

DBLocale

Specify the language/locale in which your database is installed. This will allow you to return the query in the language supported by your database. By default this attribute is set to “none”, which means that by default, queries are returned in the English locale.

ClientLocale

Specify the language/locale in which the eG agent is running. Normally, when you use an internal agent to monitor Informix, the ClientLocale and DBLocale will be same. However, the ClientLocale may differ when you are monitoring the Informix tests using a remote agent (agentless monitoring). By default, the ClientLocale is set to “none”, indicating that the eG agent runs in the English locale, by default.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Unused Indexes

Indicates the total number of unused indexes currently found in this database.

Number

Use the detailed diagnosis of this measure to know which indexes in a database are unused. The detailed diagnosis also reveals how often each such index has been updated, so that you can assess the unnecessary overheads that the database may have incurred in the process.