Ok, so AB are joined, if:
1) Both A and B have to be specified in either in WHERE-clause or GROUP BY-clause ; or one in WHERE and the other in GROUP-BY 2) The order of the Joint Dimension is or is NOT important ??? If AB is joint, then BA is also joint, right? Meaning "select ... group by B, A" or "select ... where B = xx group by A" is also valid for AB as joint-dimension ??? 3) If AB is joint and AC is joint: a. It does NOT mean that ABC is necessarily joint group, right ??? b. Also BC doesn’t have to be joint, correct ?? Thanx, Richard. From: ShaoFeng Shi [mailto:[email protected]] Sent: Thursday, June 30, 2016 7:45 PM To: [email protected] Subject: Re: Joint VS Derived This slide has introduction on the Derived Dim: http://www.slideshare.net/YangLi43/design-cube-in-apache-kylin "Joint" is introduced since 1.5.1; Using "joint" to combine multiple dimensions into "one" ; Say if you have Dim A, B, C; among them AB are always appeared together, e.g, "select ... group by A, B" or "select ... where A = xx group by B"; in this case you can declare AB as "joint"; for Kylin it looks like a 2 dim cube: AB, C, the combinations are decreased from 2^3 to 2^2; 2016-06-30 6:56 GMT+08:00 Alberto Ramón <[email protected] <mailto:[email protected]> >: Hi I don't understand the difference between: - Joint Dim (from Dimension Step ) - Derived Dim (from Advance Setings Step) Some example ? :) -- Best regards, Shaofeng Shi No virus found in this message. Checked by AVG - www.avg.com <http://www.avg.com> Version: 2016.0.7640 / Virus Database: 4613/12530 - Release Date: 07/01/16
