Re: [GENERAL] JSON to INT[] or other custom type

​You will be unable to cast the array itself.  You must use json functions to unfurl the json into a result set with each row containing a single value.  You can then explicitly cast that value to integer.  If the casting doesn't fail you now have column of integers that can be "array_agg(value_as_integer)​" to construct an SQL array of type integer[] (or whatever you decide to cast it to).

You can write you own pl/pgsql function to do these operations.

As your example includes a two-dimensional array you probably will need to json_array_elements_text twice, then array_agg twice, to get a similar structure in the eventual SQL array.

Hopefully that moves you in a useful direction.

David J.