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uwescience / raco

Compilation and rule-based optimization framework for relational algebra. Raco is the language, optimization, and query translation layer for the Myria project.
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Add a Left Join operator to Myria algebra? #402

Open billhowe opened 9 years ago

billhowe commented 9 years ago

Unless we have it in some form already.

Sp2Bench is the immediate use case.

We can fake it with inner join unioned with the stuff that fails to join, but that's a terrifyingly large amount of work compared to just emitting the left tuple padded with nulls instead of dropping it on the floor.

bmyerz commented 9 years ago

To be clear, are you proposing to: 1) add syntax to MyriaL for a left-join operator 2) add such an operator to LogicalAlgebra

billhowe commented 9 years ago

On Mon, Apr 6, 2015 at 10:40 AM, Brandon Myers notifications@github.com wrote:

To be clear, you are proposing to add syntax to MyriaL for a left-join operator and add such an operator to LogicalAlgebra?

I think so, yes.

Bill Howe Associate Director and Senior Data Science Fellow, UW eScience Institute Affiliate Faculty, Computer Science & Engineering University of Washington To acknowledge eScience: "Supported in part by the University of Washington eScience Institute"

domoritz commented 9 years ago

Left or right? Myria has a right hash join ;-)

BrandonHaynes commented 9 years ago

I also have a use-case where it would be useful to surface a left/right join at the MyriaL level.

billhowe commented 9 years ago

Left-only is ok with me. I find people expect the "root" relation to be on the left typically.

On Tue, Apr 7, 2015 at 7:14 PM, Dominik Moritz notifications@github.com wrote:

Left or right? Myria has a right hash join https://github.com/uwescience/myria/blob/master/src/edu/washington/escience/myria/operator/RightHashJoin.java ;-)

— Reply to this email directly or view it on GitHub https://github.com/uwescience/raco/issues/402#issuecomment-90781793.

Bill Howe Associate Director and Senior Data Science Fellow, UW eScience Institute Affiliate Faculty, Computer Science & Engineering University of Washington To acknowledge eScience: "Supported in part by the University of Washington eScience Institute"