When you import metadata or specify a database type in the General tab of the Database dialog, the set of SQL features for that database object is automatically populated with default values appropriate for the database type.
The Oracle BI Server uses the supported SQL features with the specified data source.
When a feature is marked as supported, checked in the Default column on the Features tab of the Database dialog, the Oracle BI Server pushes the function or calculation down to the data source for improved performance. When a function or feature is not supported in the data source, the calculation or processing is performed in the Oracle BI Server.
The supported features list uses the defaults defined in the DBFeatures.INI file, located in ORACLE_HOME/bi/bifoundation/server/bin. You should not modify this file. You can review the DBFeatures.INI file to compare the features supported by different data source types.
You can tailor the query features for a data source such as when upgrading to a new version of a data source to see if the updated feature is reflected in the Oracle BI Server defaults. When the supported feature is not shown in the Features tab, you can update the settings in the Features tab to reflect the actual features supported by the new version of the data source. If a data source supports a particular feature such as left outer join queries but you want to prohibit the Oracle BI Server from sending such queries to a particular data source, you can change this default setting in the Features tab. If you have federated data sources that execute functions differently, to ensure that query results are consistent, you can disable the appropriate functions on the Features tab so that the calculations are performed in a consistent manner in the Oracle BI Server.
Caution:
If you enable SQL features that the data source does not support, your query may return errors and unexpected results. If you disable supported SQL features, the server could issue less efficient SQL to the data source.
In most cases, you should keep the default values. If you do change the defaults to mark a feature as supported in the Features tab, make sure that the feature is actually supported by the data source.
Note:
Do not change the OPTIMIZE_MDX_FILTER_QUALIFICATION feature. This parameter is reserved for a future release.
The table lists the options available on the Features tab of the Database dialog.
| Option | Description |
|---|---|
|
Feature |
The name of the database feature, such as |
|
Value |
Shows the current value for the given feature. Selected indicates that the feature is supported in the data source, and that the function or feature should be performed in the data source rather than in the Oracle BI Server. Some features show a default value in the Value column rather than selected/not selected, such as 10 for It is strongly recommended that you keep the default selections and default values. |
|
Default |
Shows the default value for the given feature. The defaults listed in this column are specified in the file |
|
Find |
Searches for a feature in the list. |
|
Find Again |
This option becomes available after you click Find. It lets you perform multiple searches for the same string. |
|
Query DBMS |
Use Query DBMS only when you are installing and querying a data source that has no set of feature defaults in the Oracle BI Server. Query DBMS enables querying the type of data source for Feature table entries so that you can find out which SQL features are supported. You can then change the entries that appear in the Features tab based on your query results. Query DBMS is not available if you are using an XML or a multidimensional data source. Caution: Be very careful when using the Query DBMS feature. The results of the features query are not always an accurate reflection of the SQL features actually supported by the data source. When using this feature, you should verify that the list of supported features in the Features tab matches the actual features supported by your data source. Refer to the documentation for your data source for details. |
|
Reset to defaults |
This button restores the default values for this data source type from the file DBFeatures.INI. |