Thank for reply Michael. yes i understood this on the documentation for example with "WHERE" statement calcite i force the . "ALLOW FILTERING; " and this can be expensive.
I think there may be an interesting approach using STREAM. for example maintain a regular update between a cassandra TABLE and a STREAM TABLE. CASSANDRA_TABLE_A . (SELECT * FROM TABLE_A) --------> STREAM_TABLE_A . SELECT STREAM * FROM STREAM_TABLE_A WHERE username = 'JmuhsAaMdw' i guess it will be more efficient to directly make the WHERE from the STREAM than the cassandra_adapter using "allow filtering" a synchronization strategy can be set up between the cassandra table and the STREAM table what is your opinion about this approach ? Thanks ! Yana Le mer. 16 oct. 2019 à 17:08, Michael Mior <mm...@apache.org> a écrit : > You're right that there are several types which are not supported by > the Cassandra adapter. We would happily accept pull requests to add > support for new types. > > You're also correct that Cassandra cannot efficiently execute queries > which do not specify the partition key. Calcite will make those > queries more efficient, but it can make it easier to execute queries > that CQL does not directly support. Ultimately data is still stored > based on the partition key, so if your query does not specify a > partition key, Calcite will still need to issue an expensive > cross-partition query to Cassandra. > -- > Michael Mior > mm...@apache.org > > Le mer. 16 oct. 2019 à 07:57, Yanna elina <yannaelinasul...@gmail.com> a > écrit : > > > > Hi guys , > > > > I study Calcite the benefits that a Cassandra-Calcite Adapter can bring , > > as for example brings the possibility of join. > > > > the problem type defined into CassandraSchema.getRelDataType(..) is very > > limited > > some important type are missing boolean / array ect... > > > > I thought inherited from the class CassandraSchema for Override this > > method and add more type but this method is used inside CassandraTable > too. > > > > i would like to avoid to re-write fully this adapter :) > > > > do you have suggestions? > > > > My second question is : Cassandra is not optimized to have WHERE on key > > not defined on cluster/partition key. I was wondering if calcite could > play > > a role without this mechanism to improve performance > > > > > > Thank ! > > > > Yanna >
