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Reducing the database contents

The Trimble 4D Control Server technical database has some in-built procedures, which all make sure that the database entries do not sum up infinitely. These procedures all use time thresholds, which are stored in the TableLifeTime table of the database. When a Trimble 4D Control Server module creates a new table to store its data there, it automatically creates an entry for this table with default life time values in the TableLifeTime table. Thereafter, you can edit these values at any time.

The database controlling procedures run in the following order:

  1. Deletion of the oldest data after predefined periods.

    Twice a day, data older than a certain age are deleted automatically.

    The maximum age of data kept in the database depends on the table the data is written to. The maximum data age for each table is specified in its LifeTime field in the TableLifeTime table. The time units are hours.

  2. The second method applied to reduce the database size is to compute mean values for specified periods for data older than a specified age.

    Using the TableLifeTime table you have several options to modify the automatic data reduction for each data table.

  3. Deletion of the oldest data, if a specified maximum of disk space is reached.

    If the disk space a database table uses has increased up to a specified threshold, Trimble 4D Control Server automatically deletes the oldest data of the table.

    The amount of data for each table to be deleted depends on the specification in the MaxSize_MB fields of the TableLifeTime table. Typical values are NULL (that means, unlimited table size) or 10, 50, 100, or 200 MB.

Example for a typical data reduction set in the TableLifeTime table - The column headers are abbreviated for getting a better overview. For more information on the fields, see the explanation in Step 2.

Example for TableLifeTime table

Tip - You can edit the values at any time. To return to the default values for a specific table, however, you have to add the module creating it to the system under a new configuration name. This will create a new entry into the TableLifeTime table with default values that you can copy to the previously modified values.

See Also

Database maintenance

Emergency access

The technical database

Reporting - Trimble Report Generator

User rights