Read performance for SPSS categorical variables is best when the labeled values are identical either to the native values, which are in the form 1, 2, ... n, or to the sequential values 0, 1, ... (n-1), because mapping between the SPSS data values and the DSC's native values is then done by a calculation instead of by looking up the values in a list. For example, adding value labels of 98="DK" and 99="NA" to the list of value labels can reduce the read performance.

Category scanning and generation (as a result of a non-zero value of the ScanForCategories property) can impact the performance of UNICOM Intelligence Reporter when reading large .sav files. For more information, see Troubleshooting when reading from a .sav file.