Support for maintaining session data on the target server

Db2 12 introduces an enhancement to reduce network traffic through the use of session tokens on the Db2 server.

Prior to Db2 12, in order to support transaction rerouting and pooling, distributed clients needed session data (special registers and global variables) to be returned and replayed.

With Db2 12, session data is maintained on the Db2 server when clients interchange session tokens. This enhancement results in reduced network traffic.