- Berkeley DB Reference Guide:
- Access Methods
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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 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.
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