phia: don't use a generic iterator API where it's not necessary.
phia: don't use a generic iterator API where it's not necessary.

The generic, type-unsafe API is used for stream merges only.
Don't use it in places in which it obscures the code.

rtsisyk/tarantool,mejedi/tarantool,mejedi/tarantool,rtsisyk/tarantool,mejedi/tarantool,rtsisyk/tarantool,rtsisyk/tarantool,mejedi/tarantool