This section explains how you can use the option Sybase IQ provides to do disk striping, without using third party software. If you already have a disk striping solution through third party software and hardware, you should use that method instead.
The syntax you use to turn disk striping on or off is:
SET OPTION "PUBLIC".DISK_STRIPING = { ON | OFF }
The default for the DISK_STRIPING option is ON for all platforms. When disk striping is ON, incoming data is spread across all dbspaces with space available. When disk striping is OFF, dbspaces (disk segments) are filled up from the front on the logical file, filling one disk segment at a time.
You must restart the IQ server in order for a change to the value of the DISK_STRIPING option to take effect.
The database options MAIN_DISK_KB_PER_STRIPE and TEMP_DISK_KB_PER_STRIPE define the number of kilobytes (KB) to write to each dbspace before the disk striping algorithm moves to the next stripe for the IQ Main Store and the IQ Temporary Store, respectively. The default value for these options is 1, which rounds up to one page.
You can drop a dbspace using the DROP DBSPACE command when disk striping is on. Before dropping the dbspace, however, you must relocate all of the data in the dbspace using the sp_iqrelocate stored procedure. Because disk striping spreads data across multiple dbspaces, the relocation process may require the relocation of many tables and indexes. Use the sp_iqdbspaceinfo and sp_iqdbspace stored procedures to determine which tables and indexes reside on a dbspace.
