> On April 9, 2015, 1:22 a.m., Aman Sinha wrote: > > exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/join/NestedLoopJoinTemplate.java, > > lines 93-94 > > <https://reviews.apache.org/r/32945/diff/1/?file=920309#file920309line93> > > > > Will this loop work for left outer join ? Suppose the right input is > > empty, we still want to produce all left rows. e.g in the following > > example query: > > SELECT * FROM t1 > > LEFT OUTER JOIN > > (SELECT * FROM t2 WHERE 1=0) > > ON 1=1 /* for cartesian join */
Yes, currently we will not output any rows. But like discussed, we wouldn't use NLJ for generic outer joins anyways as the filter above would filter out the rows not conforming to the join condition. For outer joins we will use NLJ only with scalar sub queries. - Mehant ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/32945/#review79455 ----------------------------------------------------------- On April 9, 2015, 9:03 p.m., Mehant Baid wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/32945/ > ----------------------------------------------------------- > > (Updated April 9, 2015, 9:03 p.m.) > > > Review request for drill and Aman Sinha. > > > Repository: drill-git > > > Description > ------- > > This patch implements the nested loop join operator. The main changes are in > the files NestedLoopJoinBatch and NestedLoopJoinTemplate. This patch only > contains the execution changes. Planning patch will be posted in a separate > review request by Aman. > > > Diffs > ----- > > > exec/java-exec/src/main/java/org/apache/drill/exec/physical/base/AbstractPhysicalVisitor.java > 27b0ecb > > exec/java-exec/src/main/java/org/apache/drill/exec/physical/base/PhysicalVisitor.java > e6a89d0 > > exec/java-exec/src/main/java/org/apache/drill/exec/physical/config/NestedLoopJoinPOP.java > PRE-CREATION > > exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/join/NestedLoopJoin.java > PRE-CREATION > > exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/join/NestedLoopJoinBatch.java > PRE-CREATION > > exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/join/NestedLoopJoinBatchCreator.java > PRE-CREATION > > exec/java-exec/src/main/java/org/apache/drill/exec/physical/impl/join/NestedLoopJoinTemplate.java > PRE-CREATION > > exec/java-exec/src/main/java/org/apache/drill/exec/record/ExpandableHyperContainer.java > 90310e2 > protocol/src/main/java/org/apache/drill/exec/proto/UserBitShared.java > 9a9d196 > protocol/src/main/protobuf/UserBitShared.proto 5e44655 > > Diff: https://reviews.apache.org/r/32945/diff/ > > > Testing > ------- > > The tests are dependent on the planning changes, hence not uploaded as part > of this patch. However > https://github.com/mehant/drill/blob/notin_1/exec/java-exec/src/test/java/org/apache/drill/exec/physical/impl/join/TestNestedLoopJoin.java > is a working branch that contains a bunch of tests (planning & execution) > added for nested loop join. > > > Thanks, > > Mehant Baid > >
