TSS Enqueues

TSS uses a long-term or a short-term enqueue as necessary:

  • The long-term enqueue allows several users to update the TSS data set in shared mode, or allows one user to update the data set exclusively.
  • TSS issues the short-term enqueue to prevent possible concurrent updates during logical operations such as TSS ADD, DEFINE, LOAD, or UNLOAD. The short-term enqueue is released when the logical operation is completed and should only be held for a fraction of a second each time.

The update mode keywords EXCL, SHAR, and NONE on the ETATSS command or command statement determine how the enqueues are used. SHAR is the default.

  • SHAR allows multiple users to update the data set concurrently. TSS obtains a shared long-term enqueue when SHAR is used, and exclusive short-term enqueues are obtained as needed.
  • EXCL permits one user to update the data set exclusively. Other users may use update mode NONE, but they may not use SHAR or EXCL. TSS obtains an exclusive long-term enqueue when EXCL is used. No short-term enqueues are obtained.
  • NONE does not permit updates. TSS tables can be examined but not changed. No enqueues are obtained.

 

Tip: For faster searching, add an asterisk to the end of your partial query. Example: cert*