freebsd man page for start_transaction

START 
TRANSACTION(7)						   SQL Commands 					      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

DESCRIPTION
       This  command begins a new transaction block. If the isolation level or read/write mode is specified, the new transaction has those charac-
       teristics, as if SET TRANSACTION [set_transaction(7)] was executed. This is the same as the BEGIN [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 SQL standard requires commas between successive transaction_modes, but for historical reasons PostgreSQL allows the commas to be  omit-
       ted.

       See also the compatibility section of SET TRANSACTION [set_transaction(7)].

SEE ALSO
       BEGIN [begin(7)], COMMIT [commit(7)], ROLLBACK [rollback(7)], SAVEPOINT [savepoint(7)], SET TRANSACTION [set_transaction(7)]

SQL - Language Statements					    2010-05-14						      START TRANSACTION(7)