test=# select * from test1 ;
 id | value
----+-------
  1 |    11
  2 |    21
  3 |    31
(3 rows)

test=# begin;
BEGIN

test=# update test1 set value = value + 1;
UPDATE 3

test=# update test1 set value = value + 10;
server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.
The connection to the server was lost. Attempting reset: Succeeded.

test=# update test1 set value = value + 100;
UPDATE 3

test=# commit;
NOTICE:  there is no transaction in progress
COMMIT

test=# select * from test1 ;
 id | value
----+-------
  1 |   111
  2 |   121
  3 |   131
(3 rows)