This manual page describes the specific details of the DbTxn class.
The DbTxn class is used in conjunction with DbTxnMgr to provide transaction semantics. Full transaction support is provided by a collection of modules that provide interfaces to the services required for transaction processing. These services are recovery (see DbLog), concurrency control (see DbLock and DbLockTab) and the management of shared data (see DbMpool and DbMpoolFile).
Transaction semantics can be applied to the access methods described in Db through method call parameters.
The model intended for transactional use (and the one that is used by the access methods) is write-ahead logging provided by DbLog to record both before- and after-images. Locking follows a two-phase protocol, with all locks being released at transaction commit.
See the Reference Guide for more information.