Updates to cost model
Project: http://git-wip-us.apache.org/repos/asf/incubator-quickstep/repo Commit: http://git-wip-us.apache.org/repos/asf/incubator-quickstep/commit/d725bcaf Tree: http://git-wip-us.apache.org/repos/asf/incubator-quickstep/tree/d725bcaf Diff: http://git-wip-us.apache.org/repos/asf/incubator-quickstep/diff/d725bcaf Branch: refs/heads/transitive-closure Commit: d725bcafec86b7637ce08a24c309b2ea1981a618 Parents: a08044e Author: Jianqiao Zhu <jianq...@cs.wisc.edu> Authored: Fri Dec 1 17:20:25 2017 -0600 Committer: Jianqiao Zhu <jianq...@cs.wisc.edu> Committed: Fri Dec 1 17:20:25 2017 -0600 ---------------------------------------------------------------------- query_optimizer/cost_model/StarSchemaSimpleCostModel.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/incubator-quickstep/blob/d725bcaf/query_optimizer/cost_model/StarSchemaSimpleCostModel.cpp ---------------------------------------------------------------------- diff --git a/query_optimizer/cost_model/StarSchemaSimpleCostModel.cpp b/query_optimizer/cost_model/StarSchemaSimpleCostModel.cpp index f7417b6..729a563 100644 --- a/query_optimizer/cost_model/StarSchemaSimpleCostModel.cpp +++ b/query_optimizer/cost_model/StarSchemaSimpleCostModel.cpp @@ -486,7 +486,7 @@ std::size_t StarSchemaSimpleCostModel::getNumDistinctValues( return stat.getNumDistinctValues(rel_attr_id); } } - return estimateCardinalityForTableReference(table_reference); + return estimateCardinalityForTableReference(table_reference) * 0.5; } bool StarSchemaSimpleCostModel::impliesUniqueAttributes( @@ -520,7 +520,7 @@ bool StarSchemaSimpleCostModel::impliesUniqueAttributes( std::static_pointer_cast<const P::TableReference>(physical_plan); const CatalogRelationStatistics &stat = table_reference->relation()->getStatistics(); - if (stat.hasNumTuples()) { + if (stat.isExact() && stat.hasNumTuples()) { const std::size_t num_tuples = stat.getNumTuples(); for (const auto &attr : attributes) { const attribute_id rel_attr_id =
