Why Cassandra connector fetches entire table data?

[vijaynm]

I have created VDB with Cassandra as datasource. In Cassandra I have column family called "Person". My VDB configuration looks like below

    <model name="CassandraaDB" visible="true">
        <source name="cassandraDB" connection-jndi-name="java:/cassandraDS" translator-name="cassandra"/>
    </model>

    <model name="TeiidTables" visible="true">
        <source name="cassandraDB" translator-name="cassandra" connection-jndi-name="java:/cassandraDS" />
        <metadata type="DDL"><![CDATA[
            CREATE FOREIGN TABLE Person (
                 nr integer,     
                 country varchar,
                 name varchar,
                 PRIMARY KEY (nr)
            );
         ]]>
        </metadata>
    </model>

While debugging the performance issues, what I have observed is, if I execute the below query using Teiid JDBC Driver

select * from CassandraDB.Person where country = 'US'

Teiid fetches the entire table content, and returns the result (so it is very slow), where as below query fetches only the matching records (very fast)

select * from TeiidTables.Person where country = 'US'

I could not understand the reason? any explanation please?

I am using Teiid 9.1.1 + JDK 6 + Cassandra 2.1.16

[rareddy]

Can you see if you can grab the DDL of schema from first scenario and matches with the second?

I believe the built-in metadata importer (in the first case) automatically sets "searchable" property on "country" to true if this column is indexed in Cassandra. Where as in the second form there is no searchability. It is defined here Cassandra Translator · Teiid Documentation

so you can change

<model name="TeiidTables" visible="true"> 
  <source name="cassandraDB" translator-name="cassandra" connection-jndi-name="java:/cassandraDS" /> 
  <metadata type="DDL"><![CDATA[
    CREATE FOREIGN TABLE Person (
      nr integer,     
      country varchar OPTIONS(SEARCHABLE 'SEARCHABLE'),
      name varchar,
      PRIMARY KEY (nr)
    );
  ]]> 
  </metadata>
</model>

[shawkins]

Yes, this should be addressed at the same time as [TEIID-4717] Add Support for 'ALLOW FILTERING' in Teiid Cassandra Translator - JBoss Issue Tracker

If that is what you are working on see teiid/CassandraMetadataProcessor.java at master · teiid/teiid · GitHub for the importer logic.