Monitoring locking and database performance

The Progress Monitor (PROMON) utility helps you monitor database activity and performance. PROMON also provides advanced options (called R&D options) for in-depth monitoring of database activity and performance.

Virtual system tables give ABL and OpenEdge SQL applications access to the same type of database information that you collect with the PROMON utility. Virtual system tables (VSTs) enable an application to examine the status of a database and monitor its performance. With the database broker running, ABL and OpenEdge SQL applications can call a VST and retrieve the specified information as run-time data. The following virtual system tables relate to locking:

Lock Table Activity (_ActLock) — Displays lock-table activity, including the number of share, exclusive, upgrade, Rec Get, and redundant requests; the number of exclusive, Rec Get, share, and upgrade grants; the number of exclusive, Rec Get, share, and upgrade waits; the number of downgrades, transactions committed, cancelled requests, and database up time.

Lock Table Status File (_Lock) — Displays the status of the lock table, including the user number, the user name, lock type, record ID, number, flags, and chain.

Lock Request File (_LockReq) — Displays information about lock requests, including user name and number, record locks and waits, information schema locks and waits, and transaction locks and waits.

Record Locking Table File (_UserLock) — Reports the first 512 lock entries for a particular user with one request to the lock subsystem. It is a "snapshot" picture of each user per "_user-lock" record and not a changing picture as is each "_lock."