Processing, DBUTLTY and SQL Messages › CA Datacom/DB Processing Messages (DB0xxxxc) › DB02311I

DB02311I

PLEXLVL x, BASE - nnnn Y-nn STS-aa

Reason:

The x (as described below) in the message is either MULTIPLE +LOCKS, MULTIPLE -LOCKS, or SINGLE.

In the Y-nn field, the nn is two MUFplex numbers. The first is the MUF issuing the message. The second is the MUF controlling the change in status. The status is the single or the multiple with or without locks.

In the STS-aa field, the aa is two positions for modes S/A and 7 for mode B. Each MUF by number has the letter U if a currently open for update URT, R for a currently read URT (and no update URT), O for a currently open but no open URT, or . (a period) if this MUF is not enabled. For example:

DB02311I - PLEXLVL MULTIPLE +LOCKS, BASE---897 Y-12 STS-UU
DB02311I - PLEXLVL MULTIPLE +LOCKS, BASE---897 Y-22 STS-UU

DB02311I - PLEXLVL SINGLE, BASE---897 Y-11 STS-OU
DB02311I - PLEXLVL SINGLE, BASE---897 Y-21 STS-OU

In the examples just shown, the first UU is the two MUFs necessary to switch to multiple +locks. When the update URT closed on MUF 1, it drove the lowering of status to single. The second Muf to open the update URT was MUF 2.

All messages only occur when running with the MUFPLEX MUF startup option enabled.

PLEXLVL MULTIPLE +LOCKS, BASE - nnnn

This message occurs when a database is being opened for an update user, and it is found that one other Multi-User Facility currently has this base open with an update user. This other Multi-User Facility might currently be enabled or could have previously existed and not cleanly ended through an EOJ. In this message, MULTIPLE indicates more than one Multi-User Facility is involved, and as part of the events of this message all index and data buffers in memory are locked using the Coupling Facility (future buffer accesses are also locked). The +LOCKS in the message is used because, with update users on two Multi-User Facilities, full row locking must now also be started for all current and future row locks.

PLEXLVL MULTIPLE -LOCKS, BASE - nnnn

This message can occur for either of two reasons:

• When a database is being opened, it is found that one other Multi-User Facility currently has this database open, and one or both of the opens are without update. This can indicate either two read-only users, or one read-only user and one update user.
• A database with open update users on two Multi-User Facilities has a User Requirements Table closed such that now one of the Multi-User Facilities no longer has an update user.

  The -LOCKS in the message indicates the multiple Multi-User Facilities that are involved, so that buffer sharing with locks is required, but no row locking is required since only one Multi-User Facility is reading rows with locks and optionally performing maintenance.

PLEXLVL SINGLE, BASE - nnnn

This message occurs when a database is having a URT closed and the number of Multi-User Facilities with open User Requirements Tables for this database is going from two to one. With only one Multi-User Facility, having a database open with users, no row Coupling Facility locking is required and no Coupling Facility buffer locking is required.

Note: Additional overhead in Coupling Facility usage does occur when a database is open with User Requirements Tables on multiple Multi-User Facilities in a MUFplex.

Action:

None. This message is for information only.