The amount of memory available for use as a database server cache is one of the key factors controlling performance. You can
set the initial amount of cache memory using the -c server option. The more cache memory that can be given to the database
server, the better its performance.
The size is the amount of memory, in bytes. Use k, m, or g to specify units of kilobytes, megabytes, or gigabytes, respectively.
The unit p is a percentage either of the total physical system memory, or of the maximum supported cache size, whichever is lower. The
maximum supported cache size depends on the operating system. For example:
2.5 GB for Windows 32-bit Advanced Server, Enterprise Server, Datacenter Server, and Vista
3.5 GB for the 32-bit database server running on Windows x64 Edition
1.5 GB on all other 32-bit Windows operating systems
On Windows Mobile, the cache size is limited by available physical memory
On 64-bit database servers, the cache size can be considered unlimited
If you use p, the argument is a percentage. You can use % as an alternative to p, but on Windows operating systems, which use % as an environment variable escape character, you must escape the % character.
For example, to set the initial cache size to 50 percent of the physical system memory, run the following command:
dbsrv16 -c 50%% ...
If no -c option is provided, the database server calculates the initial cache allocation as follows:
If you attempt to set your initial or minimum cache sizes to a value that is less than one eighth of the maximum cache size,
the initial and minimum cache sizes are automatically increased relative to the maximum cache size.