CHAPTER 12 Managing System Resources
441
•
To set the maximum number of threads a single user will use, issue the
command
SET OPTION MAX_IQ_THREADS_PER_CONNECTION
. This
can be used to control the amount of memory a particular operation
consumes. For example, the DBA can set this option before issuing an
INSERT
or
LOAD
command.
Balancing I/O
This section explains the importance of balancing I/O on your system. It
explains how to use disk striping and how to locate files on separate disks to
gain better performance.
Raw I/O (on UNIX operating systems)
Most UNIX files systems divide disks into fixed size partitions. Partitions are
physical subsets of the disk that are accessed separately by the operating
system. Disk partitions are typically accessed in two modes: cooked mode
(through the UFS file system) or raw mode. Raw mode (sometimes called
character mode) does unbuffered I/O, generally making a data transfer to or
from the device with every read or write system call. The UFS (cooked) mode
is a UNIX file system and a buffered I/O system which collects data in a buffer
until it can transfer an entire buffer at a time.
When you create a database or a dbspace, you can place it on either a raw
device or a file system file. Adaptive Server IQ determines automatically from
the pathname you specify whether it is a raw partition or a file system file. Raw
partitions can be up to 128GB.
For more information, see “Working with databases”.
Summary of Contents for Adaptive Server IQ 12.4.2
Page 1: ...Administration and Performance Guide Adaptive Server IQ 12 4 2 ...
Page 16: ...xvi ...
Page 20: ...Related documents xx ...
Page 40: ...Compatibility with earlier versions 20 ...
Page 118: ...Troubleshooting startup shutdown and connections 98 ...
Page 248: ...Importing data by replication 228 ...
Page 306: ...Integrity rules in the system tables 286 ...
Page 334: ...Cursors in transactions 314 ...
Page 396: ...Users and permissions in the system tables 376 ...
Page 438: ...Determining your data backup and recovery strategy 418 ...
Page 484: ...Network performance 464 ...
Page 500: ...System utilities to monitor CPU use 480 ...
Page 514: ...Characteristics of Open Client and jConnect connections 494 ...
Page 536: ...Index 516 ...