Advanced Queuing - Oracle

Converting Messages
The transformation is always in the context of the gateway agent, which means that
the gateway agent user must have execute privileges on the transformation function
and the AQ payload type. This can be accomplished by granting the EXECUTE
privilege to PUBLIC, or by granting the EXECUTE privilege directly to the gateway
agent user.
Message Conversion for MQSeries
The Messaging Gateway MQSeries driver converts between the internal message
format and the MQSeries native message format. MQSeries native messages consist
of a fixed message header and a message body. The message body is treated as
either a TEXT value or RAW (bytes) value.
Figure 18–4 illustrates the message conversion performed by the MQSeries driver.
For outbound propagation, the driver maps the AQ message properties and
canonical message to a native message having a fixed header and message body.
For inbound propagation, the driver maps a native message to a set of AQ message
properties and a canonical message.
Figure 18–4 MQSeries Message Conversion
Messaging Gateway
Message
AQ Property
Canonical Header
Canonical Body
For outbound propagation, an MGW_BASIC_MSG_T canonical message is mapped to
an MQSeries native message as follows:
18-32 Oracle9i Application Developer’s Guide - Advanced Queuing
MQSeries
Message
Header
Body
Outbound
Propagation
Inbound
Propagation