User Guide

SAP AG November 2002
Requester
The requester is a special thread [Page 17]. The requester receives both local communication
requests (CONNECT) and requests from the network and assigns them to a user kernel
thread (UKT) [Page 14] .
Temporary Dev Thread
Temporary dev threads (asdev<i>) (which are special threads [Page 17]) are activated to
read and write data for data backups [Page 131].
Timer
The timer is a special thread [Page 17]. The timer monitors time for timeout control.
Operating-System-Dependent Special Threads
A database instance [Page 132] has the following operating-system-dependent special
threads [Page 151]:
• Clock Thread [Page
18]
• Console Thread [Page
18]
Clock Thread
The clock thread is an operating-system dependent special thread [Page 18]. The clock
thread is only used under Windows NT.
It computes internal times; for example, to determine the time needed to execute an SQL
statement.
Console Thread
The console thread is an operating-system dependent special thread [Page 18].
Windows NT/Windows 2000 UNIX
Requests from the
XCONS console
The console thread processes
requests from the XCONS console.
The XCONS program
communicates with the console
thread for this purpose.
The XCONS console receives the
necessary information directly from
the shared memory of the threads.
knldiag file
The console thread collects all
database instance [Page
132]
messages from the other threads
and lo
g
s these in a file called
The knldiag file is created. Each
thread writes information to this file.
User Manual: SAP DB 18