Berkeley DB Reference Guide: Access Methods
Description: Berkeley DB: An embedded database programmatic toolkit.
Keywords: embedded,database,programmatic,toolkit,b+tree,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,java,C,C++

### Berkeley DB Reference Guide: Access Methods |

# Retrieving records

The DB->get function is the standard interface for retrieving 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, i.e., 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 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.

Copyright Sleepycat Software