enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Rollback (data management) - Wikipedia

    en.wikipedia.org/wiki/Rollback_(data_management)

    SQL refers to Structured Query Language, a kind of language used to access, update and manipulate database. In SQL, ROLLBACK is a command that causes all data changes since the last START TRANSACTION or BEGIN to be discarded by the relational database management systems (RDBMS), so that the state of the data is "rolled back" to the way it was before those changes were made.

  3. Compensating transaction - Wikipedia

    en.wikipedia.org/wiki/Compensating_transaction

    Each transaction may consist of several individual operations yet, as a whole, it moves the system between consistent states. There are two groups of systems where compensating transaction may be applied: 1. In the context of a database this is often easily achieved using transactions and the commit/rollback mechanism. [1]

  4. Database trigger - Wikipedia

    en.wikipedia.org/wiki/Database_trigger

    TRANSACTION START; TRANSACTION COMMIT (exceptions raised here prevent the transaction from committing, or preparing if a two-phase commit is involved) TRANSACTION ROLLBACK; Database-level triggers can help enforce multi-table constraints, or emulate materialized views. If an exception is raised in a TRANSACTION COMMIT trigger, the changes made ...

  5. Savepoint - Wikipedia

    en.wikipedia.org/wiki/Savepoint

    A savepoint is a way of implementing subtransactions (also known as nested transactions) within a relational database management system by indicating a point within a transaction that can be "rolled back to" without affecting any work done in the transaction before the savepoint was created. Multiple savepoints can exist within a single ...

  6. Commit (data management) - Wikipedia

    en.wikipedia.org/wiki/Commit_(data_management)

    The transaction, commit and rollback concepts are key to the ACID property of databases. [1] A COMMIT statement in SQL ends a transaction within a relational database management system (RDBMS) and makes all changes visible to other users. The general format is to issue a BEGIN WORK (or BEGIN TRANSACTION, depending on the database vendor ...

  7. Database transaction - Wikipedia

    en.wikipedia.org/wiki/Database_transaction

    A database transaction symbolizes a unit of work, performed within a database management system (or similar system) against a database, that is treated in a coherent and reliable way independent of other transactions. A transaction generally represents any change in a database. Transactions in a database environment have two main purposes:

  8. Two-phase commit protocol - Wikipedia

    en.wikipedia.org/wiki/Two-phase_commit_protocol

    The coordinator sends a rollback message to all the participants. Each participant undoes the transaction using the undo log, and releases the resources and locks held during the transaction. Each participant sends an acknowledgement to the coordinator. The coordinator undoes the transaction when all acknowledgements have been received.

  9. Transaction processing - Wikipedia

    en.wikipedia.org/wiki/Transaction_processing

    It is also possible to keep a separate journal of all modifications to a database management system. (sometimes called after images).This is not required for rollback of failed transactions but it is useful for updating the database management system in the event of a database failure, so some transaction-processing systems provide it.