LOCKLISTSTATISTICS

Definition

The statistics system table LOCKLISTSTATISTICS contains information about the used space in the lock list.

Structure

LOCKLISTSTATISTICS

DESCRIPTION

CHAR(40)

Description of how to interpret the content of the VALUE column (see table Column DESCRIPTION)

VALUE

CHAR(12)

Value

DESCRIPTION Column

Value

Explanation

MAX LOCKS

VALUE contains the number of available locks in the lock list

TRANS LIST REGIONS

VALUE contains the number of semaphores for transactions

TABLE LIST REGIONS

VALUE contains the number of semaphores for tables

ROW LIST REGIONS

VALUE contains the number of the semaphore for rows

ENTRIES

VALUE contains an internal measure (entries) for the lock list size

USED ENTRIES

VALUE contains the number of entries for locks and lock requests

USED ENTRIES(%)

VALUE contains the percentage of entries used for locks and lock requests

AVG USED ENTRIES

VALUE contains the average number of entries used for locks and lock requests

AVG USED ENTRIES(%)

VALUE contains the average percentage of entries used for locks and lock requests

MAX USED ENTRIES

VALUE contains the maximum number of entries for locks and lock requests

MAX USED ENTRIES(%)

VALUE contains the maximum percentage of entries used for locks and lock requests

LOCK ESCALATION VALUE

VALUE contains the number of table rows from which the lock rows are converted into table locks (lock escalation)

LOCK ESCALATIONS

VALUE contains the number of lock escalations

LOCK COLLISIONS

VALUE contains the number of lock requests that could not be satisfied (immediately)

DEADLOCKS

VALUE contains the number of situations where at least two transactions collided with each other due to held and requested locks in such a way that this collision can be resolved only by implicitly ending a transaction

SQL REQUEST TIMEOUTS

VALUE contains the number of lock requests that could not be satisfied because they had exceeded the maximum wait time

TRANSACTIONS HOLDING LOCKS

VALUE contains the number of transactions with assigned locks

TRANSACTIONS REQUESTING LOCKS

VALUE contains the number of transactions requesting locks

CHECKPOINT WANTED

If the VALUE column contains the value TRUE, the lock list is closed, i.e. no exclusive lock can be assigned to a transaction without exclusive lock because a checkpoint was requested

SHUTDOWN   WANTED

If the column VALUE contains the value TRUE, the lock list is closed because a shutdown was requested

See also:

Concepts of the Database System, Locking for Database Objects