Why do native CQL functions like MIN() and MAX() not work in Amazon Keyspaces?

Question

I'm trying to retrieve the max value of a column in my aws keyspace table using python. I have it as a method in a class

        query = SimpleStatement('select min (timestamp) from '  + keyspace + '.'+ table_name) #+ ' limit 2'
        read = self.session.execute(query)
        
        return read.current_rows

That is my read function, and I call it :

access.read_latest_timestamp('gdapp_finance','policy_test').

I get the below error. Can someone assist me please.

InvalidRequest                            Traceback (most recent call last)
/tmp/ipykernel_223/2808458841.py in <module>
----> 1 access.read_latest_timestamp('gdapp_finance','policy_test')

/tmp/ipykernel_223/1193162473.py in read_latest_timestamp(self, keyspace, table_name)
     58         query = SimpleStatement('select min (timestamp) from '  + keyspace + '.'+ table_name , \
     59                                consistency_level=ConsistencyLevel.ONE) #+ ' limit 2'
---> 60         read = self.session.execute(query)
     61 
     62         return read.current_rows

~/.local/lib/python3.9/site-packages/cassandra/cluster.cpython-39-x86_64-linux-gnu.so in cassandra.cluster.Session.execute()

~/.local/lib/python3.9/site-packages/cassandra/cluster.cpython-39-x86_64-linux-gnu.so in cassandra.cluster.ResponseFuture.result()

InvalidRequest: Error from server: code=2200 [Invalid query] message="min is not yet supported." ```

Answer 1

AWS Keyspaces only supports a subset of native CQL functions. Functions like MIN() and MAX() are not supported.

Similarly, user-defined functions and aggregates are not supported either.

For the list of supported Cassandra functions, see Built-in functions in Amazon Keyspaces.

For the list of supported Cassandra APIs, see Supported Cassandra APIs, operations, and data types in Amazon Keyspaces. Cheers!