Chapter 5. The DB

Chapter 5. The DB_ENV Handle
Prev		Next

Chapter 5. The DB_ENV Handle

The DB_ENV object is the handle for a Berkeley DB environment — a collection including support for some or all of caching, locking, logging and transaction subsystems, as well as databases and log files. Methods of the DB_ENV handle are used to configure the environment as well as to operate on subsystems and databases in the environment.

DB_ENV handles are created using the db_env_create method, and are opened using the DB_ENV->open() method.

When you are done using your environment, close it using the DB_ENV->close() method. Before closing your environment, make sure all open database handles are closed first. See the DB->close() method for more information.

Database Environments and Related Methods

Database Environment Operations	Description
DB->get_env()	Return the DB's underlying DB_ENV handle
DB_ENV->close()	Close an environment
db_env_create	Create an environment handle
DB_ENV->dbremove()	Remove a database
DB_ENV->dbrename()	Rename a database
DB_ENV->err()	Error message
DB_ENV->failchk()	Check for thread failure
DB_ENV->fileid_reset()	Reset database file IDs
DB_ENV->get_home()	Return environment's home directory
DB_ENV->get_open_flags()	Return flags with which the environment was opened
DB_ENV->lsn_reset()	Reset database file LSNs
DB_ENV->open()	Open an environment
DB_ENV->remove()	Remove an environment
DB_ENV->stat_print()	Environment statistics
db_strerror	Error strings
db_version	Return version information
Environment Configuration
DB_ENV->add_data_dir()	add an environment data directory
DB_ENV->set_alloc()	Set local space allocation functions
DB_ENV->set_app_dispatch()	Configure application recovery callback
DB_ENV->set_data_dir(), DB_ENV->get_data_dirs()	Set/get the environment data directory
DB_ENV->set_create_dir(), DB_ENV->get_create_dir()	add an environment data directory
DB_ENV->set_encrypt(), DB_ENV->get_encrypt_flags()	Set/get the environment cryptographic key
DB_ENV->set_event_notify()	Set event notification callback
DB_ENV->set_errcall()	Set error message callbacks
DB_ENV->set_errfile(), DB_ENV->get_errfile()	Set/get error message FILE
DB_ENV->set_errpfx(), DB_ENV->get_errpfx()	Set/get error message prefix
DB_ENV->set_feedback()	Set feedback callback
DB_ENV->set_flags(), DB_ENV->get_flags()	Environment configuration
DB_ENV->set_intermediate_dir_mode(), DB_ENV->get_intermediate_dir_mode()	Set/get intermediate directory creation mode
DB_ENV->set_isalive()	Set thread is-alive callback
DB_ENV->set_msgcall()	Set informational message callback
DB_ENV->set_msgfile(), DB_ENV->get_msgfile()	Set/get informational message FILE
DB_ENV->set_shm_key(), DB_ENV->get_shm_key()	Set/get system memory shared segment ID
DB_ENV->set_thread_count(), DB_ENV->get_thread_count()	Set/get approximate thread count
DB_ENV->set_thread_id()	Set thread of control ID function
DB_ENV->set_thread_id_string()	Set thread of control ID format function
DB_ENV->set_timeout(), DB_ENV->get_timeout()	Set/get lock and transaction timeout
DB_ENV->set_tmp_dir(), DB_ENV->get_tmp_dir()	Set/get the environment temporary file directory
DB_ENV->set_verbose(), DB_ENV->get_verbose()	Set/get verbose messages
DB_ENV->set_cachesize(), DB_ENV->get_cachesize()	Set/get the environment cache size