When the DB2 subsystem resides in the linklist and no plan or SSID is specified, how is the plan for Easytrieve's program invoked without an explicit plan specified?
CA Easytrieve's plan is invoked dynamically in place of a explicit plan specification. The SSID comes from the SDSNEXIT in the JCL or from the options table.
Page A-28 of the CA-Easytrieve Plus release 6.4 Getting Started Guide has this documented for the SSID parameter:
Specifies a valid connection ID for the given database management system. The valid formats are as follows:
DB2 for OS/390 and z/OS.xxxx/yyyyyyyy where xxxx is a valid DB2 for OS/390 and z/OS subsystem ID and yyyyyyyy is a valid DB2 for OS/390 and z/OS location ID.
Neither value is required. Either one can be specified. If a location ID is specified, it must be preceded by a slash, such as SSID=/yyyyyyyy.
If no SSID is specified, the DB2 for OS/390 and z/OS subsystem is obtained from the DB2 for OS/390 and z/os default module DSNHDECP found through the DB2 for OS/390 and z/OS library, specified in your JOBLIB or STEPLIB JCL.
Override is through the SSID parameters of the PARM statement.
Documentation is also found in the r11.6 User Guide on page 51 of Chapter 2.