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4.6. Tuning the Database Settings for Searches

The Directory Server Console only shows the databases that contain the directory data and the NetscapeRoot database. However, the server uses another database to manage these. On this database, the following attributes can be changed to improve performance:
  • The amount of memory to make available for all databases (maximum cache size), which is described in Section 6.3, “Setting the Entry Cache Size”.
  • The maximum number of entries for the server to verify in response to a search request (look-through limit).
  • The amount of memory to make available for import (import cache size).
To configure the default database attributes that apply to all other database instances:
  1. In the Directory Server Console, select the Configuration tab; then, in the navigation tree, expand the Data icon, and highlight the Database Settings node.
  2. Select the LDBM Plug-in Settings tab in the right pane.
    This tab contains the database attributes for all databases stored on this server.
  3. In the Maximum Cache Size field, enter a value corresponding to the amount of memory to make available for all databases. This value is for the total of the entire backend, meaning all databases cumulatively rather than the amount per single database instance.
  4. In the Look-Through Limit field, enter the maximum number of entries for the server to check in response to a search request.
  5. There are two ways to set the amount of memory in bytes to make available for import. The default is to have auto cache sizing, meaning 50% of the free memory is allocated for the import cache. It is also possible to set the import cache size manually by deselecting the Use Cache Auto-Size check box and then setting the value in the Import Cache Size field. For creating a very large database from LDIF, set this attribute as large as possible, depending on the memory available on the machine. The larger this parameter, the faster the database is created.


    Setting this value too high can cause import failures because of a lack of memory.