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Jonathan Ellis commented on CASSANDRA-2480: ------------------------------------------- where do we actually compare it w/ another buffer? > Named keys / virtual columns > ---------------------------- > > Key: CASSANDRA-2480 > URL: https://issues.apache.org/jira/browse/CASSANDRA-2480 > Project: Cassandra > Issue Type: Sub-task > Components: API, Core > Reporter: Eric Evans > Assignee: Pavel Yaskevich > Labels: cql > Fix For: 0.8.1, 1.0 > > Attachments: 2480-v4-wip.txt, CASSANDRA-2480-v2.patch, > CASSANDRA-2480-v3.patch, CASSANDRA-2480.patch > > > With the completion of CASSANDRA-2396, it is now possible to attach a name to > keys (column family-wide). This could be utilized to introduce the concept > of "virtual columns" in CQL. Here's how that would work: > Typically you would use the CQL keyword {{KEY}} to specify a row key, for > example: > {code:SQL|title=CQL 1.0} > INSERT INTO cf (KEY, name1, name2) VALUES (key1, value1, value2) > -- or alternately > UPDATE cf SET name1 = value1, name2 = value2 WHERE KEY = key1 > SELECT name1,name2 FROM cf WHERE KEY = key1 > {code} > For CQL 1.1, that syntax would continue to work, but upon the completion of > this issue it should also be possible to assign a name to the key and treat > as if it were another column. For example: > {code:SQL|title=CQL 1.1} > INSERT INTO cf (keyname, name1, name2) VALUES (key1, value1, value2) > -- or alternately > UPDATE cf SET name1 = value1, name2 = value2 WHERE keyname = key1 > -- Note how the keyname can now be used in the projection > SELECT keyname, name1, name2 FROM cf WHERE keyname = key1 > -- And, there is no restriction on the order > SELECT name1, name2, keyname FROM cf WHERE keyname = key1 AND name2 = value2 > {code} > The semantics will be such that the existing behavior is maintained (read: > when using the {{KEY}} keyword), but if the key is named, and the name is > used in a {{SELECT}}, the key's name and value will be returned in the column > results, sorted according to the comparator (_Note: we'll need to figure out > what that means with respect to differently typed keys_). -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira