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Robert Stupp updated CASSANDRA-7813: ------------------------------------ Attachment: 7813v4.txt > Decide how to deal with conflict between native and user-defined functions > -------------------------------------------------------------------------- > > Key: CASSANDRA-7813 > URL: https://issues.apache.org/jira/browse/CASSANDRA-7813 > Project: Cassandra > Issue Type: Improvement > Reporter: Sylvain Lebresne > Assignee: Robert Stupp > Labels: cql > Fix For: 3.0 > > Attachments: 7813.txt, 7813v2.txt, 7813v3.txt, 7813v4.txt > > > We have a bunch of native/hardcoded functions (now(), dateOf(), ...) and in > 3.0, user will be able to define new functions. Now, there is a very high > change that we will provide more native functions over-time (to be clear, I'm > not particularly for adding native functions for allthethings just because we > can, but it's clear that we should ultimately provide more than what we > have). Which begs the question: how do we want to deal with the problem of > adding a native function potentially breaking a previously defined > user-defined function? > A priori I see the following options (maybe there is more?): > # don't do anything specific, hoping that it won't happen often and consider > it a user problem if it does. > # reserve a big number of names that we're hoping will cover all future need. > # make native function and user-defined function syntactically distinct so it > cannot happen. > I'm not a huge fan of solution 1). Solution 2) is actually what we did for > UDT but I think it's somewhat less practical here: there is so much types > that it makes sense to provide natively and so it wasn't too hard to come up > with a reasonably small list of types name to reserve just in case. This > feels a lot harder for functions to me. > Which leaves solution 3). Since we already have the concept of namespaces for > functions, a simple idea would be to force user function to have namespace. > We could even allow that namespace to be empty as long as we force the > namespace separator (so we'd allow {{bar::foo}} and {{::foo}} for user > functions, but *not* {{foo}} which would be reserved for native function). -- This message was sent by Atlassian JIRA (v6.3.4#6332)