The process of committing a distributed transaction in two phases. In the first phase, the transaction processor checks that all parts of the transaction can be committed. In the second phase, all parts of the transaction are committed. If any part of the transaction indicates in the first phase that it cannot be committed, the second phase does not occur. ODBC does not support two-phase commits.
The protocol that transaction monitors use in guaranteeing that a set of operations are completed as a unit.
A two-step process by which recoverable resources and an external subsystem are committed. During the first step, the database manager subsystems are polled to ensure that they are ready to commit. If all subsystems respond positively, the database manager instructs them to commit.
A mechanism to synchronize updates on different machines or platforms so that they all fail or all succeed together. The decision to commit is centralized, but each participant has the right to veto. This is a key process in real time transaction-based environments.
The process by which distributed transactions occur. In a two-phase commit, each node commits its changes and signals that it has completed. When all nodes have successfully committed, the distributed transaction has committed. UPDATE--The SQL statement used to change rows in a table.
A process by which consistency is maintained across data sources. In the first phase, the prepare phase, all participants (databases or other resources managers) in a transaction are polled to see if they are prepared to commit a transaction. In the second phase, the commit phase, if all of the participants responded affirmatively to the prepare phase, the transaction will be committed; on the other hand, if any of the participants responded negatively, the transaction will be rolled back.
A protocol for the coordination of changes to recoverable resources when more than one resource manager is used by a single transaction. Contrast with single-phase commit.
Method for co-ordinating a single transaction across two or more database management systems or other resource managers. Two-phase commit guarantees the logical integrity of data by ensuring that transaction updates are finalised ("committed") in all of the separate databases or are fully backed out of all participating databases, i.e., all or nothing based on transaction boundaries. Two-phase commit is a necessary component of distributed database and is implemented in " transaction management" software, which may be part of a database management system, on-line transaction processing monitor, or front-end application tool.
A method used by a distributed DBMS to ensure that every local database participating in a single multi-node, transaction commits or rolls back, in order to ensure data integrity across all nodes. Each commit actually involves two phases: preparation and verification for the commit and the actual commit.
A strategy in which changes to a database are temporarily applied. Once it has been determined that all parts of a change can be made successfully, the changes are permanently posted to the database.