+IBerkeley DB: Dbc[P

Dbc





#include <db_cxx.h>







Description



AThis manual page describes the specific details of the Dbc class,ewhich provides cursor support for the access methods in Db.

AThe Dbc functions are the library interface supporting sequentialNaccess to the records stored by the access methods of the Berkeley DB library.oCursors are created by calling the Db::cursor method which returns apointer to a Dbc object.

MEach cursor maintains positioning information within a set of key/data pairs.BIn the presence of transactions, cursors are only valid within the=context of a single transaction, the one specified during the;Db::cursor call.JAll cursor operations will be executed in the context of that transaction.IBefore aborting or committing a transaction, all cursors used within thattransaction must be closed.tIn the presence of transactions, the application must call DbTxn::abortJif any of the cursor operations returns that a deadlock (EAGAIN) or systemfailure occurred.

KWhen locking is enabled, page locks are retained between consecutive cursorcalls.HFor this reason, in the presence of locking, applications should discard+cursors as soon as they are done with them.qCalling the Db::close method discards any cursors opened in the context‹of a particular Db object returned by the Db::open call.



Class

Dbc



See Also

6Dbc::close,2Dbc::del,1Dbc::getand2Dbc::put.
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