Sets the maximum size of a single file in the log, in bytes. The value set for this parameter may not be larger than the maximum unsigned four-byte value.

When the logging subsystem is configured for on-disk logging, the default size of a log file is 10MB.

When the logging subsystem is configured for in-memory logging, the default size of a log file is 256KB. In addition, the configured log buffer size must be larger than the log file size. (The logging subsystem divides memory configured for in-memory log records into "files", as database environments configured for in-memory log records may exchange log records with other members of a replication group, and those members may be configured to store log records on-disk.) When choosing log buffer and file sizes for in-memory logs, applications should ensure the in-memory log buffer size is large enough that no transaction will ever span the entire buffer, and avoid a state where the in-memory buffer is full and no space can be freed because a transaction that started in the first log "file" is still active.

The syntax of this parameter in the DB_CONFIG file is a single line with the string set_lg_max, one or more whitespace characters, and the maximum log file size in bytes.

If the database environment already exists when this parameter is changed, it is ignored. To change this value after the environment has been created, re-create your environment.

For more information, see DB_ENV->set_lg_max() .