A type of database object that is a list of values that provide categories for data. A dimension acts as an index for identifying values of a variable. For example, if you have sales data with a separate sales figure for each month, then the data has a MONTH dimension; that is, the data is organized by month. A dimension is similar to a key in a relational database.
Any item of data within a multidimensional variable can be uniquely and completely selected by specifying one member from each of the variable's dimensions. For example, if a sales variable is dimensioned by MONTH, PRODUCT, and MARKET, specifying "January" for the MONTH dimension, "Stereos" for the PRODUCT dimension, and "Eastern Region" for the MARKET dimension uniquely specifies a single cell in the variable. Thus, dimensions offer a concise and intuitive way of organizing and selecting data for retrieval, updating, and performing calculations.
A dimension can be simple, with values that are single text or integer values, or it can be conjoint, with values that are combinations of values in other dimensions. A composite is not a dimension, but it is a conjoint-like internal object that Express treats like a dimension for the purpose of handling sparse data.