Search all columns as a single text per row Need an extension that offers a full-text-search with a kind of contains(*,text) instead to concatenate each field-value.

There are times when a formal structured query language is overkill, and the easiest way to find the right content is to perform a search, like you would with a search engine such as Google or Yahoo (...) JCR-SQL2:
SELECT * FROM [nt:base] WHERE CONTAINS([nt:base],'full-text-query')
Full+text+search example in other SQL engine
You can cast the complete row to a string (text) and then use the built-in full text search on that result:

select *
from foo
where to_tsvector(foo::text) @@ to_tsquery('full-text-query');


foo::text concatenates all columns of that table as a single large string, using the default text representation for non-text data.