Before you install Sybase IQ, consider where to put your data.
Subsequent sections introduce file placement. For performance implications, see the chapter titled “Managing System Resources” in the Sybase IQ Performance and Tuning Guide.
Several types of files can be associated with each database:
Database files
Transaction log files
Message log files
For each database you create, Sybase IQ creates four files:
A file for permanent IQ data, called the IQ Store (filename.iq by default)
A file for temporary IQ data, for sorting and other internal uses (filename.iqtmp)
A file for system information and your database schema, called the Catalog Store (filename.db)
A message log file, (filename.iqmsg)
Each database file is called a dbspace. You may need to create additional dbspaces for your IQ data. Depending on your query needs, you may need more dbspaces for temporary data as well.
Make sure that you have enough disk space for your dbspaces. Chapter 3, “Working with Database Objects” in the Sybase IQ System Administration Guide includes a procedure for estimating the disk space you need for your IQ data. For the best performance, especially with larger databases, you should spread the dbspaces for your IQ data across multiple disks.
Consider carefully where you want to place your database files. To move a database file, you must do a full backup and restore of that database.
You can put a database file—that is, a dbspace—in either a file system file or a raw partition.
File systems simplify device management, but for multiplex databases, the Main IQ Store should be on a shared raw disk.
On Windows systems, raw device access is limited to user accounts with Administrator privileges.
If you want to run the IQ servers using an account that lacks
Administrator privileges, you must enable new device access permissions
for that account after each system reboot. Use the rawaccedit utility
in Sybase IQ to set permissions for raw devices for the current
session. (To run it, type rawaccedit at
the Command Prompt from an account with Administrator privileges.)
You must run rawaccedit again after each reboot
by a user with administrator privileges for the machine.
To start IQ as a Windows Service when raw device access
is required, you must run it from an account with Administrator
privilege. For instructions on granting Administrator privilege,
see “Granting Administrator privilege to the Sybase IQ service”.
To specify a raw device in rawaccedit:
To specify a raw device that is not partitioned, simply type the physical drive number. Unpartitioned disks on a Windows system are named PhysicalDriveN, where N is a number starting with 0 and increasing as needed. To find the physical drive numbers, run Programs > Administrative Tools > Disk Administrator.
To specify a raw partition, use the letter assigned to that partition. For example:
\\.\f:
A raw partition can hold only one dbspace. The size of the dbspace is the size of the raw partition. However, you can add up to 2047 dbspaces, as long as each is stored on a different raw partition. You cannot store anything besides a main or temporary dbspace on the raw partition.
Sybase IQ records information it needs to recover from a system failure in the transaction log. The default file name extension for this file is .LOG. For the best security and performance, store the transaction log on a separate device from the database. A transaction log mirror on a separate device is also recommended for IQ databases.
The default file name extension for this file is .iqmsg. For a minor performance boost, store the IQ message log separately from the data files. The message log cannot be on a raw partition.
