Berkeley DB Reference Guide: Access Methods
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Berkeley DB Reference Guide: Access Methods

Retrieving records

The DB->get function is the standard function for retrieving records from the database. In general, the get function 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, i.e., only return if both the key and the data items match those stored in the database.

DB_RMW
Acquire write locks instead of read locks during retrieval. This can enhance performance in threaded applications where deadlock is a concern.

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.