#include <db.h>

int
DB_ENV->set_lg_max(DB_ENV *dbenv, u_int32_t lg_max);

Description

Set the maximum size of a single file in the log, in bytes. By default, or if the lg_max argument is set to 0, a size of 10MB is used. Because DB_LSN file offsets are unsigned four-byte values, the set value may not be larger than the maximum unsigned four-byte value. The size of the log file must be at least four times the size of the in-memory log buffer (see DB_ENV->set_lg_bsize).

See Log File Limits for more information.

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

The DB_ENV->set_lg_max interface may be called at any time during the life of the application. If no size is specified by the application, the size last specified for the database region will be used, or if no database region previously existed, the default will be used.

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

The database environment's log file size may also be set using the environment's DB_CONFIG file. The syntax of the entry in that file is a single line with the string "set_lg_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.

Errors

The DB_ENV->set_lg_max method may fail and return a non-zero error for the following conditions:

EINVAL

An invalid flag value or parameter was specified.

Called after DB_ENV->open was called.

The size of the log file is less than four times the size of the in-memory log buffer.

The specified log file size was too large.

The DB_ENV->set_lg_max method may fail and return a non-zero error for errors specified for other Berkeley DB and C library or system functions. If a catastrophic error has occurred, the DB_ENV->set_lg_max method may fail and return DB_RUNRECOVERY, in which case all subsequent Berkeley DB calls will fail in the same way.

Class

See Also