Each class of virtual processor is dedicated to processing
certain types of threads.
The following table shows the classes of virtual processors and
the types of processing that they do.
The number of virtual processors of each class that you configure
depends on the availability of physical processors (CPUs), hardware
memory, and the database applications in use.
Table 1. Virtual-processor classes
Virtual- processor class
Category
Purpose
ADM
Administrative
Performs administrative functions.
ADT
Auditing
Performs auditing functions.
AIO
Disk I/O
Performs nonlogging disk I/O. If KAIO is used,
AIO virtual processors perform I/O to cooked disk spaces.
BTS
Basic text searching
Runs basic text search index operations and queries.
CPU
Central processing
Runs all session threads and some system threads.
Runs thread for kernel asynchronous I/O (KAIO) where available. Can
run a single poll thread, depending on configuration.
CSM
Communications Support Module
Performs communications support service operations.
Encrypt
Encryption
Used by the database server when encryption or
decryption functions are called.
On Windows™ systems, the number of encrypt virtual
processors is always set to 1, regardless of the value that is set
in the onconfig file.
IDSXMLVP
XML publishing
Runs XML publishing functions.
JVP
Java™ UDR
Runs Java UDRs.
Contains the Java Virtual Machine
(JVM).
LIO
Disk I/O
Writes to the logical-log files (internal class)
if they are in cooked disk space.
MQ
MQ messaging
Performs MQ messaging transactions.
MSC
Miscellaneous
Services requests for system calls that require
a very large stack.
OPT
(UNIX™)
Optical
Performs I/O to optical disk.
PIO
Disk I/O
Writes to the physical-log file (internal class)
if it is in cooked disk space.
SHM
Network
Performs shared memory communication.
SOC
Network
Uses sockets to perform network communication.
tenant
Multitenancy
Runs session threads for tenant databases. Tenant
virtual processors are a special case of user-defined processors that
are specific to tenant databases.
TLI
Network
Uses the Transport Layer Interface (TLI) to perform
network communication.
classname
User defined
Runs user-defined routines in a thread-safe manner
so that if the routine fails, the database server is unaffected.
The following figure illustrates the major components and the extensibility
of the database server.Figure 1: Database
server
