ISGQUERY is the IBM® recommended replacement for the GQSCAN service.
Global resource serialization enables an installation to share symbolically named resources. Programs issue the ENQ and RESERVE macros to request access to resources; global resource serialization adds information about each requestor to the appropriate resource queue. The only way you can extract information from the resource queues is by using the ISGQUERY or GQSCAN macro.
The ISGQUERY macro allows you to obtain information about the status of each resource identified to global resource serialization, which includes information about the tasks that have requested the resource. ISGQUERY fully supports 64-bit callers.