About columns in a summary table
The columns in a summary table are dimension columns, attribute columns, and measure columns. Dimension columns group data in other columns. Measure columns contain the aggregated values that are evaluated. Some examples of dimension columns include order date, country, state, or product line. Dimension columns containing date-and-time data can be grouped in intervals, in a summary table. Depending on the type of data in a measure column, BIRT Studio makes available specific aggregate functions to use on the column. Some examples of measure columns include quantity ordered, profit, and revenue.
In a summary table, columns that provide additional information about a dimension field, are called attribute columns. For example a product name, or product code data field can be attributes of the Product Line dimension. Each dimension can contain several attribute fields.

Additional Links:

Copyright Actuate Corporation 2013 BIRT iHub 2