Connection management

How connections are managed depends on what states the SQL connection and the application process are in.

At any time:

  • An SQL connection is in one of the following states:
    • Current and held
    • Current and release-pending
    • Dormant and held
    • Dormant and release-pending
  • An application process is in the connected or unconnected state, and has a set of zero or more SQL connections. Each SQL connection is uniquely identified by the name of the database server at the other end of the connection. Only one SQL connection is active (current) at a time.

Initial state of an application process: An application process is initially in the connected state, and it has exactly one SQL connection. The server of that connection is the local DB2® subsystem.

Initial state of an SQL connection: An SQL connection is initially in the current and held state.

The following figure shows the state transitions:

Figure 1. State transitions for an SQL connection and an application process connection in a distributed unit of work
Begin figure description. A diagram shows SQL and application process connection states. The topics that follow have detailed information about the connection states. End figure description.