-ch dbeng12/dbsrv12 server option

{ dbeng12 | dbsrv12 } -ch { size[ k | m | g | p ] } ...

Windows, Unix, Mac OS X

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 total 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:

2.5 GB for Windows 32-bit Advanced Server, Enterprise Server and Datacenter Server
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. To set the initial cache size to 50 percent of the physical system memory, you would run the following command:

On 64-bit operating systems, -ch and -chx are equivalent, but -ch is recommended.

dbeng12 -ch 50%% ...

This option is ignored if you are using an AWE cache. See -cw dbeng12/dbsrv12 server option (deprecated).

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

dbeng12 -ch 2m -n silver "samples-dir\demo.db"

For information about samples-dir, see Samples directory.

-ch dbeng12/dbsrv12 server option

Syntax

Applies to

Remarks

See also

Example