START TRANSACTION

Starts a transaction block.

Synopsis

START TRANSACTION [<transaction_mode>] [, ...]

where <transaction_mode> is one of:

   ISOLATION LEVEL {SERIALIZABLE | REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED}
   READ WRITE | READ ONLY
   [NOT] DEFERRABLE

Description

START TRANSACTION begins a new transaction block. If the isolation level, read/write mode, or deferrable mode is specified, the new transaction has those characteristics, as if SET TRANSACTION was run. This is the same as the BEGIN command.

Parameters

Refer to SET TRANSACTION for information on the meaning of the parameters to this statement.

Compatibility

In the standard, it is not necessary to issue START TRANSACTION to start a transaction block: any SQL command implicitly begins a block. Greenplum Database's behavior can be seen as implicitly issuing a COMMIT after each command that does not follow START TRANSACTION (or BEGIN), and it is therefore often called 'autocommit'. Other relational database systems may offer an autocommit feature as a convenience.

The DEFERRABLE transaction_mode is a Greenplum Database language extension.

The SQL standard requires commas between successive transaction_modes, but for historical reasons Greenplum Database allows the commas to be omitted.

See also the compatibility section of SET TRANSACTION.

See Also

BEGIN, COMMIT, ROLLBACK, SAVEPOINT, SET TRANSACTION

Parent topic: SQL Commands