Performance - Background Threads Statistics

The following statistics are displayed, in the Performance output window, for each background thread:

Statistics	Description
SWA (Server Work Area)	This is the internal background thread identifier.
State	This is the state of the background thread. Active or Active slave shows that the background thread is currently working with a transaction. Inactive or Inactive slave shows a background thread that is not doing anything. 'I/O processing' means the background thread is flushing one or more transactions to disk and unused means that no background thread is using that slot.
Transaction number	This is the transaction number being processed by the background thread.
Transaction count	This is the number of transactions processed by the background thread. This gives an indication of how many background threads are needed in the system. A background thread never processes any transactions is not needed. See the System Management Handbook for further information on fine tuning the number of background threads.

Also displayed, for the database, are:

Statistics	Description
Pending background threads requests	This indicates how many transactions have yet to be processed by the database background threads. This value will grow if there are too few background threads or the background threads priority is too low.
Application waiting for transaction number	For certain operations (e.g. suspend databank), the application has to wait for the background threads to complete their tasks. If there are too few background threads it may take some time before an operation can be completed. By comparing the transaction number displayed here with those being handled by the background threads, it is possible to see how many transactions are left before the current operation can be completed.

Statistics

Description

Pending background threads requests

This indicates how many transactions have yet to be processed by the database background threads. This value will grow if there are too few background threads or the background threads priority is too low.

Application waiting for transaction number

For certain operations (e.g. suspend databank), the application has to wait for the background threads to complete their tasks. If there are too few background threads it may take some time before an operation can be completed. By comparing the transaction number displayed here with those being handled by the background threads, it is possible to see how many transactions are left before the current operation can be completed.