## Rebuild Recommender Database

The Rebuild Recommender Database page allows administrators to manually rebuild the recommender database. The recommendation system tries to provide meaningful suggestions for resources that a user may find interesting or useful. Because they are dependent on part on user activity, recommendations are only available to registered users.

Information in the recommender database is updated automatically whenever a user rates a resource record. Rebuilding the recommender database is unnecessary except when upgrading to a new version of CWIS to take advantage of any improvements to the recommender engine or when recommendations seem inaccurate, possibly because of a software bug. Recommendations will be less meaningful while the recommender database is rebuilt.

CWIS considers the content of resource records (the Title, Alternate Title, Description, and Classification metadata fields in particular) when generating recommendations. The Title and Classification fields take precedence over others.

The recommender database can be rebuilt in either the foreground or background. Rebuilding the recommender database in the foreground requires that the web browser remain on the page until the rebuild is complete, but it provides a completion time estimate and current status. Rebuilding the recommender database in the background uses background tasks and does not require that the web browser remain on the page. It does not provide a completion time estimate or current status due to the nature of background tasks, but is highly recommended because rebuilding the recommender database can take a very long time and background tasks are less performance intensive.

### See Also

- Rebuild Search Database