If I understood correctly, In PostgreSQL
use split_part
See this EXAMPLE
create table star (param text);
insert into star values ('utf8: "\xE2\x9C\x93"'),
('id: "805265"'),
('plan: initial'),
('acc: "123456"'),
('last: "1234"'),
('doc: "1281468479"'),
('validation: field'),
('commit: Accept');
and use function split_part
in SELECT query to get value of acc:
like this
select col2
from (
select split_part(param, ' ', 1) col1,
split_part(param, ' ', 2) col2
from star
) t where col1='acc:'
Note: if you want to split your field by :
then use select split_part(param, ':', 1)
and split_part(param, ':', 2) col2
so the WHERE clause should be where col1='acc'
sqlfiddle-demo