start_transaction(7) [redhat man page]

START 
TRANSACTION(7)						   SQL Commands 					      START TRANSACTION(7)

NAME

       START TRANSACTION - start a transaction block

SYNOPSIS

       START TRANSACTION [ ISOLATION LEVEL { READ COMMITTED | SERIALIZABLE } ]

   INPUTS
       None.

   OUTPUTS
       START TRANSACTION
	      Message returned if successful.

       WARNING: BEGIN: already a transaction in progress
	      If there is already a transaction in progress when the command is issued.

DESCRIPTION

       This  command  begins  a  new  transaction. If the isolation level is specified, the new transaction has that isolation level. In all other
       respects, the behavior of this command is identical to the BEGIN [begin(7)] command.

NOTES

       The isolation level of a transaction can also be set with the SET TRANSACTION [set_transaction(7)] command. If no isolation level is speci-
       fied, the default isolation level is used.

COMPATIBILITY

   SQL99
       SERIALIZABLE  is  the  default isolation level in SQL99, but it is not the usual default in PostgreSQL: the factory default setting is READ
       COMMITTED.  PostgreSQL does not provide the isolation levels READ UNCOMMITTED and REPEATABLE READ. Because of lack  of  predicate  locking,
       the SERIALIZABLE level is not truly serializable. See the User's Guide for details.

       In  SQL99  this statement can specify two other properties of the new transaction: whether the transaction is read-only and the size of the
       diagnostics area. Neither of these concepts are currently supported in PostgreSQL.

SQL - Language Statements					    2002-07-26						      START TRANSACTION(7)

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)