Set the size of the in-memory log buffer, in bytes. By default, or if
the value is set to 0, a size of 32K is used. The size of the log file
(see DbEnv::set_lg_max) must be at least four times the size of the
the in-memory log buffer.
Log information is stored in-memory until the storage space fills up
or transaction commit forces the information to be flushed to stable
storage. In the presence of long-running transactions or transactions
producing large amounts of data, larger buffer sizes can increase
The DbEnv::set_lg_bsize method configures a database environment, not only operations
performed using the specified DbEnv handle.
The DbEnv::set_lg_bsize interface may not be called after the DbEnv::open
interface is called.
If the database environment already exists when
DbEnv::open is called, the information specified to DbEnv::set_lg_bsize
will be ignored.
The DbEnv::set_lg_bsize 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 log buffer 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_bsize", 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 DbEnv::set_lg_bsize method may fail and throw an exception or return a non-zero error for the following conditions:
- An invalid flag value or parameter was specified.
Called after DbEnv::open was called.
The size of the log file is less than four times the size of the in-memory
The DbEnv::set_lg_bsize method may fail and throw an exception or return a non-zero error for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbEnv::set_lg_bsize method may fail and
either return DB_RUNRECOVERY or throw a
in which case all subsequent Berkeley DB calls will fail in the same way.
DbEnv, DbLogc, DbLsn
Logging Subsystem and Related Methods
Copyright Sleepycat Software