Cassandra: map collections with multiple datatypes

Question

As stated and discussed by Mr. Ellis in dynamic-columns/wide-rows, dynamic table is possible through Map Collection. However, I can see that this is only applicable for data with the same types. Example from the link:

CREATE TABLE users (
  user_id text PRIMARY KEY,
  name text,
  birth_year int,
  phone_numbers map
);

INSERT INTO users (user_id, name, birth_year, phone_numbers)
VALUES ('jbellis', 'Jonathan Ellis', 1976, {'home': 1112223333, 'work': 2223334444});

Both home and work phone_numbers are type integer. But we need a collection with various datatypes. Say,

Create table storage ( mobile_id int PRIMARY KEY, date timestamp, data map );

Then data contains these:

{'state': String, 'protocol': Integer, 'weight': Double, 'frame': Blob ... }

So my question is that, do we have an alternative for this? Is this possible with CQL?

Jason K. Jason K. · Accepted Answer · 2015-08-04T02:44:07

At this time, I believe that it is not possible. You would be better off using a String with some sort of type information embedded in it

ie {'home': 'int:1112223333', 'work': 'str:222-333-4444'}

or alternatively use a blob and save a language-specific map into Cassandra using the blob type and language-specific serialization to save your variable map.

Cassandra: map collections with multiple datatypes

2 Answers