When I run a SELECT JSON query on a table that contains a column of type map, the JSON output doesn’t wrap the map keys with quotes, thus creating a non-standard JSON representation, which doesn’t play along with JSON parsers very well.
Here’s an example where the map keys are actually a set:
The output is:
But what I expected was that the map key, in this case the entire integer set, would be wrapped with quotes.
The same thing happens when the key is a primitive, such as int, or when it’s another type of collection.
I tried this with the latest version of the Cassandra codebase from the repository’s trunk (1f65a12c33).