Berkeley DB

Removing Elements from a Database

The simplest way to remove elements from a database is using the DB→del interface, which takes four of the same five arguments that the DB→get and DB→put interfaces take (the difference is that there is no need to specify a data item because the delete operation is only interested in the key that you want to remove), as follows:

• db: The database handle returned by db_create.

• txnid: A transaction ID. In our simple case, we don’t expect to recover the database after an application or system crash, so we aren’t using transactions and will leave this argument unspecified.

• key: The key item for the key/data pair that we want to delete from the database.

• flags: Optional flags that modify the underlying behavior of ...