From a0c157ebd7efe9b2d60166872de44b798a9e510a Mon Sep 17 00:00:00 2001
From: xianyu-w <707512433@qq.com>
Date: Tue, 23 Jan 2024 14:42:47 +0000
Subject: [PATCH] Revise qual selectivity

---
 src/sql/optimizer/ob_opt_selectivity.cpp | 4 +++-
 src/sql/optimizer/ob_sel_estimator.cpp   | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/sql/optimizer/ob_opt_selectivity.cpp b/src/sql/optimizer/ob_opt_selectivity.cpp
index cb1d44ae7f..5ee26e5cd6 100644
--- a/src/sql/optimizer/ob_opt_selectivity.cpp
+++ b/src/sql/optimizer/ob_opt_selectivity.cpp
@@ -610,6 +610,8 @@ int ObOptSelectivity::calculate_selectivity(const OptTableMetas &table_metas,
       // do nothing
     } else if (OB_FAIL(estimator->get_sel(table_metas, ctx, single_sel, all_predicate_sel))) {
       LOG_WARN("failed to calculate one qual selectivity", KPC(estimator), K(qual), K(ret));
+    } else if (FALSE_IT(single_sel = revise_between_0_1(single_sel))) {
+      // never reach
     } else if (OB_FAIL(add_var_to_array_no_dup(all_predicate_sel, ObExprSelPair(qual, single_sel)))) {
       LOG_WARN("fail ed to add selectivity to plan", K(ret), K(qual), K(selectivity));
     } else {
@@ -630,7 +632,7 @@ int ObOptSelectivity::calculate_selectivity(const OptTableMetas &table_metas,
     } else if (OB_FAIL(estimator->get_sel(table_metas, ctx, tmp_selectivity, all_predicate_sel))) {
       LOG_WARN("failed to get sel", K(ret), KPC(estimator));
     } else {
-      selectivities.at(i) = tmp_selectivity;
+      selectivities.at(i) = revise_between_0_1(tmp_selectivity);
       if (ObSelEstType::RANGE == estimator->get_type()) {
         ObRangeSelEstimator *range_estimator = static_cast<ObRangeSelEstimator *>(estimator);
         if (OB_FAIL(add_var_to_array_no_dup(all_predicate_sel,
diff --git a/src/sql/optimizer/ob_sel_estimator.cpp b/src/sql/optimizer/ob_sel_estimator.cpp
index 8d9b1208a6..338fe2de7a 100644
--- a/src/sql/optimizer/ob_sel_estimator.cpp
+++ b/src/sql/optimizer/ob_sel_estimator.cpp
@@ -1725,7 +1725,7 @@ int ObBoolOpSelEstimator::get_sel(const OptTableMetas &table_metas,
       } else {
         // not op.
         // if can calculate null_sel, sel = 1.0 - null_sel - op_sel
-        selectivity = 1.0 - null_sel - tmp_selectivity;
+        selectivity = ObOptSelectivity::revise_between_0_1(1.0 - null_sel - tmp_selectivity);
       }
     } else {
       // for other condition, it's is too hard to consider null_sel, so ignore it.