[ https://issues.apache.org/jira/browse/CASSANDRA-4915?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sylvain Lebresne updated CASSANDRA-4915: ---------------------------------------- Attachment: 0002-Allow-non-indexed-expr-with-ALLOW-FILTERING.txt 0001-4915.txt > CQL should prevent or warn about inefficient queries > ---------------------------------------------------- > > Key: CASSANDRA-4915 > URL: https://issues.apache.org/jira/browse/CASSANDRA-4915 > Project: Cassandra > Issue Type: Improvement > Affects Versions: 0.8.0 > Reporter: Edward Capriolo > Assignee: Sylvain Lebresne > Fix For: 1.2.0 rc1 > > Attachments: 0001-4915.txt, > 0002-Allow-non-indexed-expr-with-ALLOW-FILTERING.txt > > > When issuing a query like: > {noformat} > CREATE TABLE videos ( > videoid uuid, > videoname varchar, > username varchar, > description varchar, > tags varchar, > upload_date timestamp, > PRIMARY KEY (videoid,videoname) > ); > SELECT * FROM videos WHERE videoname = 'My funny cat'; > {noformat} > Cassandra samples some data using get_range_slice and then applies the query. > This is very confusing to me, because as an end user am not sure if the query > is fast because Cassandra is performing an optimized query (over an index, or > using a slicePredicate) or if cassandra is simple sampling some random rows > and returning me some results. > My suggestions: > 1) force people to supply a LIMIT clause on any query that is going to > page over get_range_slice > 2) having some type of explain support so I can establish if this > query will work in the > I will champion suggestion 1) because CQL has put itself in a rather unique > un-sql like position by applying an automatic limit clause without the user > asking for them. I also do not believe the CQL language should let the user > issue queries that will not work as intended with "larger-then-auto-limit" > size data sets. -- 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