In the context of data management, autocommit is a mode of operation of a
database connection A database connection is a facility in computer science that allows client software to talk to database server software, whether on the same machine or not. A connection is required to send commands and receive answers, usually in the form of a r ...
. Each individual database interaction (i.e., each
SQL statement) submitted through the
database connection A database connection is a facility in computer science that allows client software to talk to database server software, whether on the same machine or not. A connection is required to send commands and receive answers, usually in the form of a r ...
in autocommit mode will be executed in its own
transaction that is implicitly committed. A
SQL statement executed in autocommit mode cannot be
rolled back.
Autocommit mode incurs per-statement
transaction overhead and can often lead to undesirable performance or resource utilization impact on the database. Nonetheless, in systems such as Microsoft SQL Server, as well as connection technologies such as ODBC and Microsoft OLE DB, autocommit mode is the default for all statements that change data, in order to ensure that individual statements will conform to the
ACID
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
(atomicity-consistency-isolation-durability) properties of transactions.
The alternative to autocommit mode (non-autocommit) means that the
SQL client
Client(s) or The Client may refer to:
* Client (business)
* Client (computing), hardware or software that accesses a remote service on another computer
* Customer or client, a recipient of goods or services in return for monetary or other valuable ...
application itself is responsible for ending transactions explicitly via the ''
commit'' or ''
rollback
In political science, rollback is the strategy of forcing a change in the major policies of a state, usually by replacing its ruling regime. It contrasts with containment, which means preventing the expansion of that state; and with détente, w ...
'' SQL commands.
Non-autocommit mode enables grouping of multiple data manipulation
SQL commands into a single
atomic transaction.
Most
DBMS
In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spa ...
(e.g.
MariaDB
MariaDB is a community-developed, commercially supported fork of the MySQL relational database management system (RDBMS), intended to remain free and open-source software under the GNU General Public License. Development is led by some of the ori ...
) force autocommit for every
DDL statement, even in non-autocommit mode. In this case, before each DDL statement, previous
DML statements in transaction are autocommitted. Each DDL statement is executed in its own new autocommit transaction.
See also
*
Commit
*
Transaction
{{reflist
Databases