BusinessObjects Enterprise Administrator's Guide

Modifying database settings for the RAS

The Database tab of the Report Application Server (RAS) in the Central Management Console lets you modify the way the server runs reports against your databases.

To modify database interaction settings for the RAS

1. Go to the Servers management area of the CMC.
2. Click the link to the RAS whose settings you want to change.
3. Make your changes on the Database tab.
4. Click either Apply or Update:
• Click Apply to submit changes and restart the server so that the changes take effect immediately.
• Click Update to save the changes. You must restart the server for the changes to take effect.

Tip:    On Windows, you can also change these settings in the CCM. Stop the RAS and view its Properties. Click the Parameters tab. From the Option Type list, select Database.

Number of database records to read when previewing or refreshing a report

The "Number of database records to read when previewing or refreshing a report" area allows you to limit the number of records that the server retrieves from the database when a user runs a query or report. This setting is particularly useful if you provide users with ad hoc query and reporting tools, and you want to prevent them from running queries that return excessively large record sets.

When the RAS retrieves records from the database, the query results are returned in batches. The "Number of records per batch" setting allows you to determine the number of records that are contained in each batch. The batch size cannot be equal to or less than zero.

Number of records to browse

The "Number of records to browse" setting allows you to specify the number of distinct records that will be returned from the database when browsing through a particular field's values. The data will be retrieved first from the client's cache—if it is available—and then from the server's cache. If the data is not in either cache, it is retrieved from the database.

Oldest on-demand data given to a client (in minutes)

The "Oldest on-demand data given to a client (in minutes)" setting controls how long the RAS uses previously processed data to meet requests. If the RAS receives a request that can be met using data that was generated to meet a previous request, and the time elapsed since that data was generated is less than the value set here, then the RAS will reuse this data to meet the subsequent request. Reusing data in this way significantly improves system performance when multiple users need the same information. When setting the value of the "oldest on-demand data given to a client" consider how important it is that your users receive up-to-date data. If it is very important that all users receive fresh data (perhaps because important data changes very frequently) you may need to disallow this kind of data reuse by setting the value to 0. This is the default on the RAS, to support the data needs of users performing ad hoc reporting.

Report Job Database Connection

The "Report Job Database Connection" settings can be used to make a trade-off between the number of database licenses you use and the performance you can expect for certain types of reports.

If you select "Disconnect when all records have been retrieved or the job is closed", the Report Application Server will automatically disconnect from the report database as soon as it has retrieved the data it needs to fulfill a request. Selecting this option limits the amount of time that RAS stays connected to your database server, and therefore limits the number of database licenses consumed by the RAS.

However, if the RAS needs to reconnect to the database to generate an on-demand sub-report or to process a group-by-on-server command for that report, performance for these reports will be significantly slower than if you had selected "Disconnect when the job is closed". (The latter option ensures that RAS stays connected to the database server until the report job is closed.)