DbEnv::set_lk_max_locks()
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## DbEnv::set_lk_max_locks()

    #include <db_cxx.h>

    int
    DbEnv::set_lk_max_locks(u_int32_t max);

Set the maximum number of locks supported by the Berkeley DB environment. 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 locks. For specific information on configuring the size of the lock subsystem, see Configuring locking: sizing the system.

The database environment's maximum number of locks may also be configured 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_locks", one or more whitespace characters, and the number of locks. 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_lk_max_locks()` method configures a database environment, not only operations performed using the specified DbEnv handle.

The `DbEnv::set_lk_max_locks()` method may not be called after the DbEnv::open() method is called. If the database environment already exists when DbEnv::open() is called, the information specified to `DbEnv::set_lk_max_locks()` will be ignored.

The `DbEnv::set_lk_max_locks()` 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.

### Parameters

#### max

The max parameter is the maximum number of locks supported by the Berkeley DB environment.

### Errors

The `DbEnv::set_lk_max_locks()` method may fail and throw a DbException exception, encapsulating one of the following non-zero errors, or return one of the following non-zero errors:

#### EINVAL

If the method was called after DbEnv::open() was called; or if an invalid flag value or parameter was specified.

### Class

DbEnv, DbLock

### See Also

Locking Subsystem and Related Methods

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