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_ENV->backup() | Hot back up an entire environment |
| DB_ENV->close() | Close an environment |
| db_env_create | Create an environment handle |
| DB_ENV->dbbackup() | Hot back up a single environment file |
| 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_full_version | Return full version information |
| DB->get_env() | Return the DB's underlying DB_ENV handle |
| DB_ENV->get_home() | Return environment's home directory |
| DB_ENV->get_open_flags() | Return flags with which the environment was opened |
| DB_ENV->log_verify() | Verify log files of an environment. |
| 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_backup_callbacks(), DB_ENV->get_backup_callbacks() | Set/get callbacks used for environment hot backups |
| DB_ENV->set_backup_config(), DB_ENV->get_backup_config() | Set/get environment hot backup configuration options |
| DB_ENV->set_data_dir(), DB_ENV->get_data_dirs() | Set/get the environment data directory |
| DB_ENV->set_data_len(), DB_ENV->get_data_len() | Set/get the command line utility byte limit |
| 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_memory_init(), DB_ENV->get_memory_init() | Set/get initial memory allocation |
| DB_ENV->set_memory_max(), DB_ENV->get_memory_max() | Set/get maximum memory allocation |
| DB_ENV->set_metadata_dir(), DB_ENV->get_metadata_dir() | Set/get the directory containing environment metadata |
| 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 |