The path of a directory to be used as the location of logging files.
Log files created by the Log Manager subsystem will be created in this
directory.
If no logging directory is specified, log files are created in the
environment home directory. See Berkeley DB File Naming for more information.
For the greatest degree of recoverability from system or application
failure, database files and log files should be located on separate
physical devices.
The DbEnv::set_lg_dir interface may only be used to configure Berkeley DB before
the DbEnv::open interface is called.
The DbEnv::set_lg_dir method either returns a non-zero error value or throws an exception that
encapsulates a non-zero error value on failure, and returns 0 on success.
The database environment's logging directory 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_dir", one or more whitespace characters,
and the directory name. Because the DB_CONFIG file is read when the database
environment is opened, it will silently overrule configuration done
before that time.