mismatch

[borota]

This works:

q)t:([]a:`a`b;b:0 1;c:"ab")

q)show t,:([]a:`c`d;c:"cd")

a b c

-----

a 0 a

b 1 b

c   c

d   d

Why this, which semantically you'd think it's exactly the same thing, doesn't work?

q)t:([]a:`a`b;b:0 1;c:"ab")

q)t:t,([]a:`c`d;c:"cd")

'mismatch

[charlie]

ideally , and ,: would have the same behaviour.

In the meantime, one workaround -

q)partialJoin:{x,$[count c:cols[x]except cols y;cols[x]#y,'count[y]#0#c#x;y]}

q)t:([]a:`a`b;b:0 1;c:"ab");t1:([]a:`c`d;c:"cd");(t,:t1)~partialJoin[t;t1]

1b

[charlie]

or more simply

partialJoin:{:x,:y}