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Stratio / cassandra-lucene-index

Lucene based secondary indexes for Cassandra
Apache License 2.0
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Support Facets #278

Closed kyleboyle closed 6 years ago

kyleboyle commented 7 years ago

Any thoughts on supporting facets? Here is a brief description of it looks on DSE:

https://docs.datastax.com/en/datastax_enterprise/5.0/datastax_enterprise/srch/queriesCql.html#queriesJSON__solrFacetquery

If it isn't planned by the stratio folks, any tips on how to get started? I'm new to the cassandra secondary index interface.

adelapena commented 7 years ago

The problem with faceting is that currently Apache Cassandra doesn't support distributed/replica side aggregations due to the problems of reconciliation in the coordinator side. When a row is requested, the coordinator uses the timestamps of the rows returned by each replica to solve conflicts. However, aggregated results (faceting is a particular case) doesn't contain such information, so there is no way to solve conflicts.

kyleboyle commented 7 years ago

Would there be a way to not do aggregation and just return multiple rows, one for each vnode. Then the client can aggregate the results if they want