The results of select() and call() function are different about asynctnt HOT 3 CLOSED

Hello. This is just how Tarantool underlying protocol works.
What you see in the CALL is that Tarantool wraps everything you return from a function into a tuple, so it would be possible to make a multi value return, like this:

function f()
    return 1, 2, 3
end

The results from function above will arrive to python as an array [1, 2, 3].
So essentially result_2 means "array of return results, containing 1 array, containing 2 tuples [20] and [42]"
The difference of return types (TarantoolTuple vs list) comes from the difference in representing tuples. When you perform a SELECT request asynctnt knows what space you are selecting from, so it wraps results to TarantoolTuple which can be used either as a list or as a dict (just like in Tarantool itself).
But when you use CALL asynctnt can make no assumptions about data nature and its structure, so it returns data as is.

So, in a few words, it is impossible to deduce anything from a CALL on a connector side.
What you see in Tarantool REPL is just an unpack() of everything returned from a function and it does not look like an array.

from asynctnt.

Ok, that makes sense, thank you. I added unpack() function:

function find(space, keys)
    local result = {}
    for i, key in pairs(keys) do
        result[i] = box.space[space]:select({key})[1]
    end
    return unpack(result)
end

Now all is well:

result_2 <Response sync=7 rowcount=2 data=[[20], [42]]>

from asynctnt.

Is everything clear, can I close the issue?

from asynctnt.