Hello,
can anybody tell me what the LEFT OUTER JOIN produces in case of non matching tuples?
I thought it would produce nulls for the right relation but a later test for IS NULL does not produce the desired solution.
Example:
left_rel has schema (s: bytearray)
right_rel has schema (s: bytearray, p: bytearray)
A = JOIN left_rel BY s LEFT OUTER, right_rel BY s;
So what is the resulting tuple in case that a value for s in 'left_rel' doesn't find a join partner in 'right_rel'?
I thought it would be: (value for s in left_rel, null, null)
But a later FILTER for null values does not produce the right result:
B = FILTER A BY right_rel : : s is null
Can anybody tell me what I got wrong?
Thx in advance,
Alex
