The database server cache is arranged in pages, which are fixed-size areas of memory. Since the server uses a single cache for the Catalog Store until it is shut down, all Catalog pages must have the same size.
A Catalog file is also arranged in pages, of size 4096, 8192, 16384, or 32768 bytes. Every database page must fit into a cache page.
You use the -gp option to set the Catalog page size explicitly. By setting -gp to the maximum size, 32768, you maximize the number of columns per table that Sybase IQ can support.
By default, the server page size is the same as the largest page size of the databases on the command line. The -gp option overrides this default. Once the server starts, you cannot load a database with a larger Catalog page size than the server. Unless you specify -gp, you cannot load a database file with a Catalog page size larger than the databases started on the command line.
If you use larger page sizes, remember to increase your cache size. A cache of the same size will accommodate only a fraction of the number of the larger pages, leaving less flexibility in arranging the space.
The -gp option and the page sizes
listed here apply to the Catalog Store only. You set the page size
for the IQ Store in the IQ PAGE SIZE parameter
of the CREATE DATABASE command. See “Choosing an IQ page size” for more information.
