Most UNIX file 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: file system 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 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. Sybase IQ determines automatically from the pathname you specify whether it is a raw partition or a file system file. Raw partitions can be any size.
For more information, see the section “Working with database objects” in Chapter 5, “Working with Database Objects” of the Sybase IQ System Administration Guide.
