Aggregate optimization settings

On the Optimization tab, specify the following options.

Keys are contiguous. Select this option if you know that all records with the same key values are grouped in the input (for example, if the input is sorted on the key fields). Doing so can improve performance.

Note: If you enable SQL pushback in SPSS Modeler and a Sort node is connected to an Aggregate node, you must select the Keys are contiguous option in the Aggregate node. This setting is required to ensure correct and efficient aggregation by indicating that the input data is already sorted and grouped by key.

Allow approximation for Median and Quartiles. The Order statistics (Median, 1st Quartile, and 3rd Quartile) are currently not supported when you process data in Analytic Server. If you use Analytic Server, you can select this checkbox to use an approximated value for these statistics instead. The approximated value is calculated by binning the data and then computing an estimate for the statistic based on the distribution across the bins. By default, this option is cleared.

Number of bins. Only available if you select the Allow approximation for Median and Quartiles checkbox. Select the number of bins to be used when estimating the statistic; the number of bins affects the Maximum error %. By default, the number of bins is 1000, which corresponds to a maximum error of 0.1% of the range.