Well, the only reason to use a string for a vector or a matrix is a more readable SQL statement. like i wrote above, with a string i only have to write:
"SELECT matrix FROM GEOMETRY"
rather than
"SELECT matrix_11, matrix_12, matrix_13,..,matrix_44 FROM GEOMETRY"
Of course, i could use the "SELECT *" method, but this is a bad idea, since i might have other fields in the same table.
I think your right, that the string variant is less performant because a float value as string uses more bytes than a simple float.
But for my editor, where absolute performance is not necessary, i'll stay with the string variant to avoid too much columns. Or any one knows a other solution with SQL?
thx for your suggestions