[feike]

You can use regexes to help you split the file into pieces (this is in PostgreSQL), I expect other dbms's to have similar functions available.

    SELECT
        lineno::int              AS line,
        ((lineno-3)/6)::smallint AS card,
        ((lineno-3)%6)::smallint AS y,
        (col - 1)::smallint      AS x,
        value::smallint          AS value
    FROM
        regexp_split_to_table($1, '\n') WITH ORDINALITY AS sub(line, lineno)
    CROSS JOIN
        regexp_split_to_table(ltrim(line, ' '), '(\s+|,)') WITH ORDINALITY AS sub2(value, col)
    WHERE
        line != ''
        AND value != ''

[vimsee]

I did not know about regexp_split_to_table() or regex functions in general in dbms, but that is very neat.