[nereids] consider numNulls in filter estimation

apache · Dec 29, 2023 · 0f692eb · 0f692eb
1 parent 3c5d5ac
commit 0f692eb
Showing 1 changed file with 3 additions and 4 deletions.
diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/FilterEstimation.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/stats/FilterEstimation.java
@@ -221,8 +221,6 @@ private Statistics estimateEqualTo(ComparisonPredicate cp, ColumnStatistic stats
         double val = statsForRight.maxValue;
         if (val > statsForLeft.maxValue || val < statsForLeft.minValue) {
             selectivity = 0.0;
-        } else if (statsForRight.isUnKnown) {
-            selectivity = 0.0;
         } else {
             selectivity = StatsMathUtil.minNonNaN(1.0, 1.0 / ndv);
         }
@@ -581,9 +579,10 @@ public Statistics visitLike(Like like, EstimationContext context) {
                     "col stats not found. slot=%s in %s",
                     like.left().toSql(), like.toSql());
             ColumnStatisticBuilder colBuilder = new ColumnStatisticBuilder(origin);
-            double selectivity = origin.ndv * DEFAULT_LIKE_COMPARISON_SELECTIVITY;
+            double selectivity = StatsMathUtil.divide(DEFAULT_LIKE_COMPARISON_SELECTIVITY, origin.ndv);
             double notNullSel = getNotNullSelectivity(origin, selectivity);
-            colBuilder.setNdv(selectivity).setCount(notNullSel * context.statistics.getRowCount()).setNumNulls(0);
+            colBuilder.setNdv(origin.ndv * DEFAULT_LIKE_COMPARISON_SELECTIVITY)
+                    .setCount(notNullSel * context.statistics.getRowCount()).setNumNulls(0);
             statsBuilder.putColumnStatistics(like.left(), colBuilder.build());
             context.addKeyIfSlot(like.left());
         }