Database: Manage Size

Overview

This feature is designed for Tracer Ensemble installations using a SQL Express database but can be applied to all SQL database types. SQL Express does not provide automatic database maintenance plans. The database is allowed to grow until it reaches a size limit that prevents further data storage. User-defined data log collection, alarm collection, global point control, system, and user change logs contribute to database growth. This feature will remove these data growth components from the database. There are two components to Manage Database Size: Database Size Management and Application Log Management.

Database Size Management

Database Size management can be applied to all SQL database types. It cannot be disabled for SQL Express databases.  With a new installation of Tracer Ensemble, application data is automatically deleted based on a schedule.  You can change the settings to one of the choices described below.

CAUTION:  Selecting one of the options to delete old data at this time will result in data log values being permanently deleted from the Tracer Ensemble database. The default value for SQL Express databases automatically enables Delete old data based on database file size of 3.5 GB (SQL Express 2005) or 9.5 GB (SQL Express 2008) and will retain 90 days worth of data.

NOTE: The maximum database size cannot exceed 1000 Gigabytes.

• Do not delete old data - select this option if you want Tracer Ensemble to continue to gather data without deleting any.  Be aware that disk space usage and system performance can both be affected if you do not delete any data.
• Delete old data based on a schedule - data beyond a specified age is routinely deleted according to a specified schedule.
• Delete old data based on database file size - the system checks the database at specified intervals and deletes the oldest data first to reduce the database to a size smaller than the maximum size.

Application Log management

Application Log Management is applied to all SQL database types. You cannot select No or set the value to unlimited for any application log setting for SQL Express databases.  You can limit the number of each type of log that is retained in the database independent of the age of the data or the size of the database.  For example, you could specify that no more than 100 user changes are retained in the database; to make room for the 101st user change log record, the database would automatically delete the oldest record to make room for the newest. Valid selection for Limit are Yes and No. Valid entries for Maximum Log Entry range from 1 – 100,000. Setting limit to No automatically changes the Maximum Log Entry value to Unlimited. You cannot set the Limit to No for SQL Express databases.

Viewing and Making changes

To view and change the database size management settings:

1. In the header, click Actions and Settings | Database Size. The current database management settings are shown on the page.
2. Click Edit to make changes.

You can also use the Database Size page to execute the currently scheduled settings without waiting for the scheduled time to expire:

1. In the header, click Actions and Settings | Database Size. The current database management settings are shown on the page.
2. Click Run Now to execute the settings.

Related topics

• User Change Log: View or Delete Entries
• Alarms: View, Acknowledge, Remove
• Process Tracker: View, Delete Items