Berkeley DB: DbEnv.set_lk_max_lockers
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++

# DbEnv.set_lk_max_lockers |

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    import com.sleepycat.db.*;

    public void set_lk_max_lockers(int max)
        throws DbException;

# Description

Set the maximum number of simultaneous locking entities supported by the Berkeley DB lock subsystem. This value is used by DbEnv.open to estimate how much space to allocate for various lock-table data structures. The default value is 1000 lockers. For specific information on configuring the size of the lock subsystem, see Configuring locking: sizing the system.

The DbEnv.set_lk_max_lockers method configures a database environment, not only operations performed using the specified DbEnv handle.

The DbEnv.set_lk_max_lockers 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_lk_max_lockers will be ignored.

The DbEnv.set_lk_max_lockers method throws an exception that encapsulates a non-zero error value on failure.

The database environment's maximum number of lockers 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_lk_max_lockers", one or more whitespace characters, and the number of lockers. Because the DB_CONFIG file is read when the database environment is opened, it will silently overrule configuration done before that time.

# Errors

The DbEnv.set_lk_max_lockers method may fail and throw an exception encapsulating a non-zero error for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

  Called after DbEnv.open was called.

The DbEnv.set_lk_max_lockers method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods. If a catastrophic error has occurred, the DbEnv.set_lk_max_lockers method may fail and throw a DbRunRecoveryException, in which case all subsequent Berkeley DB calls will fail in the same way.

# Class

DbEnv, DbLock

# See Also

Locking Subsystem and Related Methods`

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