Zoltan Borok-Nagy has uploaded this change for review. ( http://gerrit.cloudera.org:8080/9239
Change subject: IMPALA-6258: Uninitialized tuple pointers in row batch for empty rows ...................................................................... IMPALA-6258: Uninitialized tuple pointers in row batch for empty rows Tuple pointers in the generated row batches may not be initialized if a tuple has byte size 0. There are some codes which compare these uninitialized pointers against nullptr so having them uninitialized may return wrong (and non-deterministic) results, e.g.: impala::TupleIsNullPredicate::GetBooleanVal() The following query produces non-deterministic results currently: SELECT count(v.x) FROM functional.alltypestiny t3 LEFT OUTER JOIN ( SELECT true AS x FROM functional.alltypestiny t1 LEFT OUTER JOIN functional.alltypestiny t2 ON (true)) v ON (v.x = t3.bool_col) WHERE t3.bool_col = true; The alltypestiny table has 8 records, 4 records of them has the true boolean value for bool_col. Therefore, the above query is a fancy way of saying "8 * 8 * 4", i.e. it should return 256. The solution is that scanners initialize tuple pointers to a non-null value when there are no materialized slots. This non-null value is provided by the new static method called Tuple::Poison(). I extended QueryTest/scanners.test with the above query. This test executes the query against all table formats. Change-Id: I298122aaaa7e62eb5971508e0698e189519755de --- M be/src/exec/hdfs-scanner.cc M be/src/exec/kudu-scanner.cc M be/src/runtime/tuple.cc M be/src/runtime/tuple.h M testdata/workloads/functional-query/queries/QueryTest/scanners.test 5 files changed, 47 insertions(+), 3 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/39/9239/1 -- To view, visit http://gerrit.cloudera.org:8080/9239 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: I298122aaaa7e62eb5971508e0698e189519755de Gerrit-Change-Number: 9239 Gerrit-PatchSet: 1 Gerrit-Owner: Zoltan Borok-Nagy <[email protected]>
