MongoDB vs Redis, a different interpretation of what's wrong with Relational DBs

Re:MongoDB vs Redis, a different interpretation of what's wr... by davidmathers on Wednesday June 03, 2009 @10:12PM (#640842)

You can't get select, project, or cartesian product out of ismember, union, and intersection.

Sorry, I didn't mention that redis has SADD and SREM for implementing projection. I'm not sure what you mean by select. You're right about product. I think that's what's missing.

Also, union corresponds to and and intersection corresponds to or

That's exactly what I said. We both got it backwards.

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Re:MongoDB vs Redis, a different interpretation of what's wr... by kragen on Thursday June 04, 2009 @07:48AM (#641240)

Haha! You're right.

"Select" is the SPC-algebra operation which gives you the subset of a relation whose tuples satisfy some Boolean condition, e.g. firstname='bob'.

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