Use an associated source qualifier when the WebSphere MQ message data is flat file or COBOL. Without the associated source qualifier, the MQ Source Qualifier treats the message data as binary. The PowerCenter Integration Service can read binary data from the message data field up to 100 MB. It does not transform the binary data.

The associated source qualifier is specific to the format of the message data. It determines how the PowerCenter Integration Service reads the message data from WebSphere MQ.

The following table lists the two types of associated source qualifiers you can use in a WebSphere MQ mapping and the corresponding message data format:

When you add an associated source qualifier to a mapping, associate it with an MQ Source Qualifier. The association allows the PowerCenter Integration Service to read the message data from WebSphere MQ based on the transformation settings in the associated source qualifier. For example, if the source data is flat file, use a flat file Source Qualifier to read the message data.

When you associate an MQ Source Qualifier with a Source Qualifier for a flat file source definition, the Designer creates a MsgId port in the Source Qualifier with the same datatype and precision as the MsgId port in the MQ Source Qualifier. It links the MsgId ports in the MQ Source Qualifier and the Source Qualifier for the flat file source definition. The association through the MsgId preserves the relationship between the header data and the message data in the WebSphere MQ source. It allows the PowerCenter Integration Service to correlate the messages in the queue with their message data.

When you run a session, the PowerCenter Integration Service reads the messages from WebSphere MQ based on the settings of the MQ Source Qualifier. For each message that it reads, it also reads the message data according to the configurations of the Source Qualifier for the flat file source definition. Similarly, if the message data in the source is COBOL, use a Normalizer transformation to read the message data.