Berkeley DB Reference Guide: Retrieving records

Berkeley DB Reference Guide:
Access Methods

Retrieving records

The DB->get method retrieves records from the database. In general, DB->get takes a key and returns the associated data from the database.

There are a few flags that you can set to customize retrieval:

DB_GET_BOTH

Search for a matching key and data item, that is, only return success if both the key and the data items match those stored in the database.

DB_RMW

Read-modify-write: acquire write locks instead of read locks during retrieval. This can enhance performance in threaded applications by reducing the chance of deadlock.

DB_SET_RECNO

If the underlying database is a Btree, and was configured so that it is possible to search it by logical record number, retrieve a specific record.

If the database has been configured to support duplicate records, DB->get will always return the first data item in the duplicate set.