Provided by: postgresql-client-8.3_8.3.7-1_i386 bug

NAME

       BEGIN - start a transaction block

SYNOPSIS

       BEGIN [ WORK | TRANSACTION ] [ transaction_mode [, ...] ]

       where transaction_mode is one of:

           ISOLATION LEVEL { SERIALIZABLE | REPEATABLE READ | READ COMMITTED | READ UNCOMMITTED }
           READ WRITE | READ ONLY

DESCRIPTION

       BEGIN  initiates  a  transaction block, that is, all statements after a
       BEGIN command will  be  executed  in  a  single  transaction  until  an
       explicit  COMMIT  [commit(7)]  or  ROLLBACK [rollback(l)] is given.  By
       default  (without   BEGIN),   PostgreSQL   executes   transactions   in
       ‘‘autocommit’’  mode,  that  is,  each statement is executed in its own
       transaction and a commit is implicitly performed  at  the  end  of  the
       statement  (if execution was successful, otherwise a rollback is done).

       Statements are executed more quickly in a  transaction  block,  because
       transaction  start/commit  requires  significant CPU and disk activity.
       Execution of multiple statements inside a transaction is also useful to
       ensure  consistency when making several related changes: other sessions
       will be unable to see the  intermediate  states  wherein  not  all  the
       related updates have been done.

       If  the  isolation  level  or  read/write  mode  is  specified, the new
       transaction  has  those  characteristics,   as   if   SET   TRANSACTION
       [set_transaction(7)] was executed.

PARAMETERS

       WORK

       TRANSACTION
              Optional key words. They have no effect.

       Refer  to  SET  TRANSACTION [set_transaction(7)] for information on the
       meaning of the other parameters to this statement.

NOTES

       START TRANSACTION [start_transaction(7)] has the same functionality  as
       BEGIN.

       Use  COMMIT  [commit(7)]  or  ROLLBACK  [rollback(7)]  to  terminate  a
       transaction block.

       Issuing BEGIN when already inside a transaction block  will  provoke  a
       warning message. The state of the transaction is not affected.  To nest
       transactions within a transaction block, use savepoints (see  SAVEPOINT
       [savepoint(7)]).

       For  reasons  of backwards compatibility, the commas between successive
       transaction_modes can be omitted.

EXAMPLES

       To begin a transaction block:

       BEGIN;

COMPATIBILITY

       BEGIN is a PostgreSQL language extension. It is equivalent to the  SQL-
       standard   command   START  TRANSACTION  [start_transaction(7)],  whose
       reference page contains additional compatibility information.

       Incidentally, the BEGIN key word is used for  a  different  purpose  in
       embedded  SQL.  You  are  advised  to  be careful about the transaction
       semantics when porting database applications.

SEE ALSO

       COMMIT   [commit(7)],   ROLLBACK   [rollback(l)],   START   TRANSACTION
       [start_transaction(l)], SAVEPOINT [savepoint(l)]