Sets a maximum cache size, as a limit to automatic cache growth.

Syntax

{ dbsrv11 | dbeng11 } -ch { size[ k | m | g | p ] } ...

Applies to

Windows, Unix, Mac OS X

Remarks

This option limits the size of the database server cache during automatic cache growth. By default the upper limit is approximately the lower of the maximum non-AWE cache size and 90% of the physical memory of the computer.

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 physical system memory, or of the maximum non-AWE cache size, whichever is lower. The maximum non-AWE cache size depends on the operating system. For example:

If you use p, the argument is a percentage. You can use % as an alternative to P, but as most non-Unix operating systems use % as an environment variable escape character, you must escape the % character. To set the minimum cache size to 50 percent of the physical system memory, you would use the following:

This option is ignored if you are using an AWE cache. You can use the -cw option to create a larger cache using AWE. See -cw server option.

dbeng11 -ch 50%% ...

See also

• -c server option
• -ca server option
• -cc server option
• -cl server option
• -cm server option
• -cr server option
• -cs server option
• -cv server option
• Limiting cache memory use

Example

The following example starts a server named silver that has a maximum cache size of 2 MB and loads the sample database:

dbeng11 -ch 2m -n silver "samples-dir\demo.db"

For information about samples-dir, see Samples directory.