This section describes how the SPSS Statistics SAV DSC writes to a .sav file when the connection to the SPSS Statistics SAV DSC includes a UNICOM Intelligence Metadata Model (MDM) document that defines the data to be written. That could be an MDM document in an existing .mdd file, or an MDM document that has been created "on the fly" using the MDM Object Model or a read-enabled MDSC.

The SPSS Statistics SAV DSC writes data to a .sav file only, and does not create an IBM SPSS Statistics data description (.sps) file or an ASCII data file.

If the .sav file specified in the connection string does not exist, the SPSS Statistics SAV DSC creates a new file.

If the file specified in the connection string already exists, and the value of the AllowOverwrite property (see Properties and settings used by the SPSS Statistics SAV DSC is 0, the will attempt to append any new rows to the existing data. This will normally be successful provided that you have exported to the file previously and there has been no change to the structure of the data since the previous export. If the SPSS Statistics SAV DSC fails to append data to the file, for example, because of missing or conflicting columns in the existing data, it issues a warning or an error message as appropriate.

The SPSS Statistics SAV DSC also writes a SPSS WebApp (.xml) file immediately after writing the .sav file. The SPSS WebApp file provides additional information for use with SPSS WebApp. For more information, see SPSS WebApp XML file.