centos man page for start_transaction

START 
TRANSACTION(7)					  PostgreSQL 9.2.7 Documentation				      START TRANSACTION(7)

NAME
       START_TRANSACTION - start 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
       This command 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 (SET_TRANSACTION(7)) was executed. This is the same as the BEGIN(7) command.

PARAMETERS
       Refer to SET TRANSACTION (SET_TRANSACTION(7)) 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.
       PostgreSQL'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 might offer an autocommit feature as a convenience.

       The DEFERRABLE transaction_mode is a PostgreSQL language extension.

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

       See also the compatibility section of SET TRANSACTION (SET_TRANSACTION(7)).

SEE ALSO
       BEGIN(7), COMMIT(7), ROLLBACK(7), SAVEPOINT(7), SET TRANSACTION (SET_TRANSACTION(7))

PostgreSQL 9.2.7						    2014-02-17						      START TRANSACTION(7)