To query subsystem information, an application can use the IEFSSI macro or an operator can use the DISPLAY SSI command. The query request allows either an application or the operator to query the following information for all subsystems defined to the SSI:

• The subsystem name
• If the subsystem is dynamic or not dynamic
• If the subsystem is the primary subsystem
• If the subsystem is active or inactive
• If the subsystem is dynamic, whether it accepts or rejects dynamic SSI commands
• If the subsystem is active, which function codes it supports.

An application can also query the following additional information:

• The number of vector tables associated with the subsystem, with a maximum of two vector tables.
• The following information for each associated vector table:
  • If the vector table is managed by the SSI. A vector table managed by the SSI is a vector table created with the IEFSSVT REQUEST=CREATE macro.
  • A locator. This locator is a token if the vector table is managed by the SSI and is an address if the vector table is not managed by the SSI.
  • If the vector table is active.
  • The function codes supported by the vector table.