Berkeley DB Reference Guide: Access method operations

Berkeley DB Reference Guide:
Access Methods

Access method operations

Once a database handle has been created using db_create, there are several standard access method operations. Each of these operations is performed using a method referred to by the returned handle. Generally, the database will be opened using DB->open. If the database is from an old release of Berkeley DB, it may need to be upgraded to the current release before it is opened using DB->upgrade.

Once a database has been opened, records may be retrieved (DB->get), stored (DB->put), and deleted (DB->del).

Additional operations supported by the database handle include statistics (DB->stat), truncation (DB->truncate), version upgrade (DB->upgrade), verification and salvage (DB->verify), flushing to a backing file (DB->sync), and association of secondary indices (DB->associate). Database handles are eventually closed using DB->close.

Database Operations	Description
db_create	Create a database handle
DB->associate	Associate a secondary index
DB->close	Close a database
DB->compact	Compact a database
DB->cursor	Create a cursor
DB->del	Delete items from a database
DB->err, DB->errx	Error message
DB->exists	Return if an item appears in a database
DB->fd	Return a file descriptor from a database
DB->get, DB->pget	Get items from a database
DB->get_byteswapped	Return if the underlying database is in host order
DB->get_type	Return the database type
DB->join	Perform a database join on cursors
DB->key_range	Return estimate of key location
DB->open	Open a database
DB->put	Store items into a database
DB->remove	Remove a database
DB->rename	Rename a database
DB->set_priority	Set cache page priority
DB->stat, DB->stat_print	Database statistics
DB->sync	Flush a database to stable storage
DB->truncate	Empty a database
DB->upgrade	Upgrade a database
DB->verify	Verify/salvage a database
Database Configuration
DB->set_alloc	Set local space allocation functions
DB->set_cachesize	Set the database cache size
DB->set_dup_compare	Set a duplicate comparison function
DB->set_encrypt	Set the database cryptographic key
DB->set_errcall, DB->set_msgcall	Set error and informational message callback
DB->set_errfile, DB->set_msgfile	Set error and informational message FILE
DB->set_errpfx	Set error message prefix
DB->set_feedback	Set feedback callback
DB->set_flags	General database configuration
DB->set_lorder	Set the database byte order
DB->set_pagesize	Set the underlying database page size
Btree/Recno Configuration
DB->set_append_recno	Set record append callback
DB->set_bt_compare	Set a Btree comparison function
DB->set_bt_minkey	Set the minimum number of keys per Btree page
DB->set_bt_prefix	Set a Btree prefix comparison function
DB->set_re_delim	Set the variable-length record delimiter
DB->set_re_len	Set the fixed-length record length
DB->set_re_pad	Set the fixed-length record pad byte
DB->set_re_source	Set the backing Recno text file
Hash Configuration
DB->set_h_compare	Set a Hash comparison function
DB->set_h_ffactor	Set the Hash table density
DB->set_h_hash	Set a hashing function
DB->set_h_nelem	Set the Hash table size
Queue Configuration
DB->set_q_extentsize	Set Queue database extent size