Hi,
last year I did a performance audit of some applications and I found a new relatively common pattern - iteration over jsonb arrays. Because PL/pgSQL doesn't support this iteration directly, they used some combinations of jsonb_array_elements function and FOR IN SELECT.
The overhead of this can be relatively high, and I think we can support FOREACH json(b) arrays without some high cost.
My idea is a support of syntax
FOREACH target IN JSON ARRAY expression LOOP .. END LOOP
target can be a scalar variable of any type - we can use cast rules used in JSON_TABLE
What do you think about this proposal?
Regards
Pavel
