Matthew Jacobs has posted comments on this change. Change subject: IMPALA-4738: STDDEV_SAMP should return NULL for single record input ......................................................................
Patch Set 1: (2 comments) http://gerrit.cloudera.org:8080/#/c/5800/1/be/src/exprs/aggregate-functions-ir.cc File be/src/exprs/aggregate-functions-ir.cc: PS1, Line 1348: DoubleVal AggregateFunctions::KnuthStddevFinalize(FunctionContext* ctx, : const StringVal& state_sv) { : DCHECK(!state_sv.is_null); : DCHECK_EQ(state_sv.len, sizeof(KnuthVarianceState)); : KnuthVarianceState* state = reinterpret_cast<KnuthVarianceState*>(state_sv.ptr); : if (state->count == 0 || state->count == 1) return DoubleVal::null(); : re > STDDEV is an alias for STDDEV_SAMP according the impala documentation. Shou If that's the case, though it is concerning Oracle's behavior differs. I see postgres does just alias them, so I guess that's fine as long as we're clear in the docs. Thanks for checking that. http://gerrit.cloudera.org:8080/#/c/5800/1/testdata/workloads/functional-query/queries/QueryTest/aggregation.test File testdata/workloads/functional-query/queries/QueryTest/aggregation.test: PS1, Line 26: SELECT variance(tinyint_col), stddev(smallint_col), variance_pop(int_col), : stddev_pop(bigint_col) please add a col for stddev_samp as well. even though they're aliased now, let's make sure we cover both fns anyway for the future. -- To view, visit http://gerrit.cloudera.org:8080/5800 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: Ide8af752cd8a2e554a2cd5a1ec948967a80de1fe Gerrit-PatchSet: 1 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: anujphadke <[email protected]> Gerrit-Reviewer: Matthew Jacobs <[email protected]> Gerrit-Reviewer: anujphadke <[email protected]> Gerrit-HasComments: Yes
