SQL processing

For each SQL statement that is processed there are a number of activities that can occur. These activities vary depending on thread reuse and the BIND options.

  • For the first SQL call in a transaction reusing a thread with a new authorization ID the following actions can occur:
    • Signon
    • Authorization check
  • Load the SKCT SQL section, if it is not already in the EDM pool.
  • Create a copy of the SKCT SQL section in the CT, if it is not already there.
  • Acquire referenced TS locks, if not already taken.
  • Load DBDs in the EDM pool, if they are not already there.
  • Process the SQL statement.

If the SQL statement is in a package, the SKPT directory and header are loaded. The PT is allocated at statement execution time, rather than at thread creation time, as in the case with the SKCT and the CT for binding plans.