#include <db.h>

int
DB_ENV->set_cache_max(DB_ENV *dbenv, u_int32_t gbytes, u_int32_t bytes);

int
DB_ENV->get_cache_max(DB_ENV *dbenv, u_int32_t *gbytesp, u_int32_t *bytesp);

The DB_ENV->set_cache_max method sets the maximum cache size, in bytes. The specified size is rounded to the nearest multiple of the cache region size, which is the initial cache size divided by the number of regions specified to the DB_ENV->set_cachesize method. If no value is specified, it defaults to the initial cache size.

The database environment's maximum cache size may also be configured using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "set_cache_max", one or more whitespace characters, and the size in bytes. Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.

The DB_ENV->set_cache_max method configures a database environment, not only operations performed using the specified DB_ENV handle.

The DB_ENV->set_cache_max method may be called at any time during the life of the application.

The DB_ENV->set_cache_max method returns a non-zero error value on failure and 0 on success.

• The mp_mmapsize parameter is the maximum file size, in bytes, for a file to be mapped into the process address space.

The DB_ENV->set_cache_max method may fail and return one of the following non-zero errors:

• If the method was called after DB_ENV->open was called; or if an invalid flag value or parameter was specified.

The DB_ENV->get_cache_max method returns the maximum size of the cache.

The DB_ENV->get_cache_max method may be called at any time during the life of the application.

The DB_ENV->get_cache_max method returns a non-zero error value on failure and 0 on success.

• The bytesp parameter references memory into which the additional bytes of memory in the cache is copied.

• The gbytesp parameter references memory into which the gigabytes of memory in the cache is copied.