DbEnv::set_lk_tablesize()

#include <db_cxx.h>

int
DbEnv::set_lk_tablesize(u_int32_t tablesize); 

Sets the number of buckets in the lock object hash table in the Berkeley DB environment. The default value is estimated based on defaults, initial and (deprecated) maximum settings of the number of lock objects allocated. The maximum memory allocation is also considered. The table is generally set to be close to the number of lock objects in the system to avoid collisions and delay in processing lock operations.

The database environment's tablesize 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_tablesize", one or more whitespace characters, and the size of the table. 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_tablesize() method configures a database environment, not only operations performed using the specified DbEnv handle.

The DbEnv::set_lk_tablesize() 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_tablesize() will be ignored.

The DbEnv::set_lk_tablesize() 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

tablesize

The tablesize parameter provides the size of the lock object hash table to be configured in the Berkeley DB environment.

Errors

The DbEnv::set_lk_tablesize() 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