Before you install Sybase IQ, consider where to put your data.
Subsequent sections introduce file placement. For details about where to place files for the best possible performance, see the chapter entitled “Managing System Resources” in the Sybase IQ Performance and Tuning Guide.
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 message log file, (filename.IQMSG)
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)
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.
Wherever the server is started is the default directory
for all database files created by Sybase IQ.
Make sure that you have enough disk space for your dbspaces. The chapter “Working with Database Objects” in the Sybase IQ System Administration Guide includes a procedure for estimating the disk space you will 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.
You can put a database file—that is, a dbspace—in either a file system file or a raw partition.
In a production environment, for some applications that use databases on UNIX servers, raw partition installations may provide increased processing performance. File systems, on the other hand, make it easier to manage your devices.
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 many as you need to hold your database, 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 in the transaction log information it needs to recover from a system failure. The default filename extension for this file is .LOG. You should store the transaction log on a separate device from the database for greater security, as well as for better performance. A transaction log mirror on a separate device is also recommended for IQ databases.
Only a small amount of information goes to the IQ message log. The default filename extension for this file is.iqmsg. For a minor performance boost, store the message log separately from the data files. A message log cannot be on a raw partition.
