[jira] [Assigned] (CASSANDRA-4476) Support 2ndary index queries with only non-EQ clauses
[ https://issues.apache.org/jira/browse/CASSANDRA-4476?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Robbie Strickland reassigned CASSANDRA-4476: Assignee: Robbie Strickland Support 2ndary index queries with only non-EQ clauses - Key: CASSANDRA-4476 URL: https://issues.apache.org/jira/browse/CASSANDRA-4476 Project: Cassandra Issue Type: Improvement Components: API, Core Reporter: Sylvain Lebresne Assignee: Robbie Strickland Priority: Minor Labels: cql Fix For: 2.1.1 Currently, a query that uses 2ndary indexes must have at least one EQ clause (on an indexed column). Given that indexed CFs are local (and use LocalPartitioner that order the row by the type of the indexed column), we should extend 2ndary indexes to allow querying indexed columns even when no EQ clause is provided. As far as I can tell, the main problem to solve for this is to update KeysSearcher.highestSelectivityPredicate(). I.e. how do we estimate the selectivity of non-EQ clauses? I note however that if we can do that estimate reasonably accurately, this might provide better performance even for index queries that both EQ and non-EQ clauses, because some non-EQ clauses may have a much better selectivity than EQ ones (say you index both the user country and birth date, for SELECT * FROM users WHERE country = 'US' AND birthdate 'Jan 2009' AND birtdate 'July 2009', you'd better use the birthdate index first). -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Assigned] (CASSANDRA-4476) Support 2ndary index queries with only non-EQ clauses
[ https://issues.apache.org/jira/browse/CASSANDRA-4476?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Jonathan Ellis reassigned CASSANDRA-4476: - Assignee: Marcus Eriksson Support 2ndary index queries with only non-EQ clauses - Key: CASSANDRA-4476 URL: https://issues.apache.org/jira/browse/CASSANDRA-4476 Project: Cassandra Issue Type: Improvement Components: API, Core Reporter: Sylvain Lebresne Assignee: Marcus Eriksson Priority: Minor Fix For: 2.0 Currently, a query that uses 2ndary indexes must have at least one EQ clause (on an indexed column). Given that indexed CFs are local (and use LocalPartitioner that order the row by the type of the indexed column), we should extend 2ndary indexes to allow querying indexed columns even when no EQ clause is provided. As far as I can tell, the main problem to solve for this is to update KeysSearcher.highestSelectivityPredicate(). I.e. how do we estimate the selectivity of non-EQ clauses? I note however that if we can do that estimate reasonably accurately, this might provide better performance even for index queries that both EQ and non-EQ clauses, because some non-EQ clauses may have a much better selectivity than EQ ones (say you index both the user country and birth date, for SELECT * FROM users WHERE country = 'US' AND birthdate 'Jan 2009' AND birtdate 'July 2009', you'd better use the birthdate index first). -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira
