In the Query section, a computed item is a set of instructions to the database server. Interactive Reporting uses the computing power of the database server to perform calculations as it retrieves data from the database.
For this reason, the Query section allows you to use computed items in a way that is not possible in the other sections. Instead of creating a new data item, the new values simply replace the original values in the data item as they are retrieved from the database.
Additionally, you can compute items using any topic item in the data model and any scalar functions provided by your RDBMS.
Since computed items are new data items, you may want to confirm or change the new item’s data type to preserve the precision of a mixed-data type computations, or to change the way a data item is handled (for example, interpreting number as strings). This ensures the correct handling of data in server computations.
Attention to data types is most important when computing items in the Query section. Here the computation is performed on the database server, and the computed item may be handled with an unanticipated data type.
Local calculations (Results, Pivot) are handled internally, and adjustment between 16- and 32-bit integers, for example, can be handled safely using the automatic or number data type specification. For a list of supported data types, see below:
Table 119. Data Types and Specifications