Inquiring about and setting object attributes

Attributes are the properties that define the characteristics of a WebSphere® MQ object.

They affect the way that a queue manager processes an object. The attributes of each type of WebSphere MQ object are described in detail in Attributes of objects.

Some attributes are set when the object is defined, and can be changed only by using the WebSphere MQ commands; an example of such an attribute is the default priority for messages put on a queue. Other attributes are affected by the operation of the queue manager and can change over time; an example is the current depth of a queue.

You can inquire about the current values of most attributes using the MQINQ call. The MQI also provides an MQSET call with which you can change some queue attributes. You cannot use the MQI calls to change the attributes of any other type of object; instead you must use:

For WebSphere MQ for Windows, UNIX and Linux® platforms: The MQSC facility, described in MQSC reference.

Note: The names of the attributes of objects are shown in this documentation in the form that you use them with the MQINQ and MQSET calls. When you use WebSphere MQ commands to define, alter, or display the attributes, you must identify the attributes using the keywords shown in the descriptions of the commands in the topic links.

Both the MQINQ and the MQSET calls use arrays of selectors to identify those attributes that you want to inquire about or set. There is a selector for each attribute that you can work with. The selector name has a prefix, determined by the nature of the attribute:

MQCA_ These selectors refer to attributes that contain character data (for example, the name of a queue).

MQIA_ These selectors refer to attributes that contain either numeric values (such as CurrentQueueDepth, the number of messages on a queue) or a constant value (such as SyncPoint, whether the queue manager supports syncpoints).

Before you use the MQINQ or MQSET calls your application must be connected to the queue manager, and you must use the MQOPEN call to open the object for setting or inquiring about attributes. These operations are described in Connecting to and disconnecting from a queue manager and Opening and closing objects.

Use the following links to find out more about getting inquiring about and setting object attributes: