Getting Started with DB2 Express-C

Chapter 6 – DB2 Architecture 111
previous versions of DB2.
Table 6.1 – Common DB2 processes
Thread Name
db2sysc
db2tcpcm
db2agent
db2agntp
db2pfchr
db2pclnr
Description
The system controller thread. This thread is responsible for the start-up
and shut-down and the management of the running instance
TCP/IP communication listener
Coordinator agent that performs database operations on behalf of
applications (at least 1 per connection, depending if Connection
Concentrator is enabled).
Active subagent spawned if INTRA_PARALLEL is set to YES. This
thread performs database operations for the application. db2agent will
coordinate the work between the different db2agntp subagents.
DB2 asynchronous I/O data prefetcher (NUM_IOSERVERS)
DB2 asynchronous I/O data writer (NUM_IOCLEANERS)
Table 6.2 – Common DB2 threads
6.2 DB2 memory model
The DB2 memory model consists of different areas in memory at the instance level,
database level, and application and agent level as shown in Figure 6.2. We will not explain
in detail each of the different areas in memory in this book, but just provide a brief
overview.