Get rid of DbSettings.optimizeIsNull

h2/src/main/org/h2/engine/DbSettings.java

@@ -206,12 +206,6 @@ public class DbSettings extends SettingsBase {
      */
     public final boolean optimizeInSelect = get("OPTIMIZE_IN_SELECT", true);
 
-    /**
-     * Database setting <code>OPTIMIZE_IS_NULL</code> (default: false).<br />
-     * Use an index for condition of the form columnName IS NULL.
-     */
-    public final boolean optimizeIsNull = get("OPTIMIZE_IS_NULL", true);
-
     /**
      * Database setting <code>OPTIMIZE_OR</code> (default: true).<br />
      * Convert (C=? OR C=?) to (C IN(?, ?)).

h2/src/main/org/h2/expression/condition/Comparison.java

@@ -397,12 +397,8 @@ public class Comparison extends Condition {
             if (l != null) {
                 switch (compareType) {
                 case IS_NULL:
-                    if (session.getDatabase().getSettings().optimizeIsNull) {
-                        filter.addIndexCondition(
-                                IndexCondition.get(
-                                        Comparison.EQUAL_NULL_SAFE, l,
-                                        ValueExpression.getNull()));
-                    }
+                    filter.addIndexCondition(
+                            IndexCondition.get(Comparison.EQUAL_NULL_SAFE, l, ValueExpression.getNull()));
                 }
             }
             return;

h2/src/main/org/h2/index/IndexCursor.java

@@ -33,7 +33,6 @@ import org.h2.value.ValueNull;
  */
 public class IndexCursor implements Cursor {
 
-    private Session session;
     private final TableFilter tableFilter;
     private Index index;
     private Table table;
@@ -75,7 +74,6 @@ public class IndexCursor implements Cursor {
      * @param indexConditions Index conditions.
      */
     public void prepare(Session s, ArrayList<IndexCondition> indexConditions) {
-        this.session = s;
         alwaysFalse = false;
         start = end = null;
         inList = null;
@@ -142,14 +140,6 @@ public class IndexCursor implements Cursor {
                     inList = null;
                     inResult = null;
                 }
-                if (!session.getDatabase().getSettings().optimizeIsNull) {
-                    if (isStart && isEnd) {
-                        if (v == ValueNull.INSTANCE) {
-                            // join on a column=NULL is always false
-                            alwaysFalse = true;
-                        }
-                    }
-                }
             }
         }
         if (inColumn != null) {
@@ -239,13 +229,11 @@ public class IndexCursor implements Cursor {
         } else if (b == null) {
             return a;
         }
-        if (session.getDatabase().getSettings().optimizeIsNull) {
-            // IS NULL must be checked later
-            if (a == ValueNull.INSTANCE) {
-                return b;
-            } else if (b == ValueNull.INSTANCE) {
-                return a;
-            }
+        // IS NULL must be checked later
+        if (a == ValueNull.INSTANCE) {
+            return b;
+        } else if (b == ValueNull.INSTANCE) {
+            return a;
         }
         int comp = table.getDatabase().compare(a, b);
         if (comp == 0) {