null in where clause can be used instead of NaN

core/src/main/java/com/nfsdb/ql/ops/FunctionFactories.java

@@ -137,10 +137,35 @@ public final class FunctionFactories {
                     break;
                 case STRING:
                     if (vc.getFlyweightStr(null) == null) {
+                        ColumnType t = sig.paramTypes.getQuick(0);
                         if (Chars.equals(sig.name, '=')) {
-                            return StrEqualsNullOperator.FACTORY;
+                            switch (t) {
+                                case DOUBLE:
+                                    return DoubleEqualsNanOperator.FACTORY;
+                                case STRING:
+                                    return StrEqualsNullOperator.FACTORY;
+                                case INT:
+                                    return IntEqualsNaNOperator.FACTORY;
+                                case LONG:
+                                case DATE:
+                                    return LongEqualsNaNOperator.FACTORY;
+                                default:
+                                    break;
+                            }
                         } else if (Chars.equals(sig.name, "!=")) {
-                            return StrNotEqualsNullOperator.FACTORY;
+                            switch (t) {
+                                case DOUBLE:
+                                    return DoubleNotEqualsNanOperator.FACTORY;
+                                case STRING:
+                                    return StrNotEqualsNullOperator.FACTORY;
+                                case INT:
+                                    return IntNotEqualsNaNOperator.FACTORY;
+                                case LONG:
+                                case DATE:
+                                    return LongNotEqualsNaNOperator.FACTORY;
+                                default:
+                                    break;
+                            }
                         }
                     }
                     break;

core/src/main/java/com/nfsdb/ql/parser/VirtualColumnBuilder.java

 /*******************************************************************************
- *    ___                  _   ____  ____
- *   / _ \ _   _  ___  ___| |_|  _ \| __ )
- *  | | | | | | |/ _ \/ __| __| | | |  _ \
- *  | |_| | |_| |  __/\__ \ |_| |_| | |_) |
- *   \__\_\\__,_|\___||___/\__|____/|____/
- *
+ * ___                  _   ____  ____
+ * / _ \ _   _  ___  ___| |_|  _ \| __ )
+ * | | | | | | |/ _ \/ __| __| | | |  _ \
+ * | |_| | |_| |  __/\__ \ |_| |_| | |_) |
+ * \__\_\\__,_|\___||___/\__|____/|____/
+ * <p>
  * Copyright (C) 2014-2016 Appsicle
- *
+ * <p>
  * This program is free software: you can redistribute it and/or  modify
  * it under the terms of the GNU Affero General Public License, version 3,
  * as published by the Free Software Foundation.
- *
+ * <p>
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Affero General Public License for more details.
- *
+ * <p>
  * You should have received a copy of the GNU Affero General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
+ * <p>
  * As a special exception, the copyright holders give permission to link the
  * code of portions of this program with the OpenSSL library under certain
  * conditions as described in each individual source file and distribute
@@ -30,7 +30,6 @@
  * delete this exception statement from your version. If you delete this
  * exception statement from all source files in the program, then also delete
  * it in the license file.
- *
  ******************************************************************************/
 
 package com.nfsdb.ql.parser;
@@ -64,18 +63,10 @@ class VirtualColumnBuilder implements PostOrderTreeTraversalAlgo.Visitor {
     private CharSequenceIntHashMap columnNameHistogram;
     private CharSequenceObjHashMap<Parameter> parameterMap;
 
-    public VirtualColumnBuilder(PostOrderTreeTraversalAlgo algo) {
+    VirtualColumnBuilder(PostOrderTreeTraversalAlgo algo) {
         this.algo = algo;
     }
 
-    public VirtualColumn createVirtualColumn(QueryModel model, ExprNode node, RecordMetadata metadata) throws ParserException {
-        this.columnNameHistogram = model.getColumnNameHistogram();
-        this.parameterMap = model.getParameterMap();
-        this.metadata = metadata;
-        algo.traverse(node, this);
-        return stack.poll();
-    }
-
     @Override
     public void visit(ExprNode node) throws ParserException {
         int argCount = node.paramCount;
@@ -115,6 +106,14 @@ class VirtualColumnBuilder implements PostOrderTreeTraversalAlgo.Visitor {
         }
     }
 
+    VirtualColumn createVirtualColumn(QueryModel model, ExprNode node, RecordMetadata metadata) throws ParserException {
+        this.columnNameHistogram = model.getColumnNameHistogram();
+        this.parameterMap = model.getParameterMap();
+        this.metadata = metadata;
+        algo.traverse(node, this);
+        return stack.poll();
+    }
+
     @SuppressFBWarnings({"LEST_LOST_EXCEPTION_STACK_TRACE"})
     private VirtualColumn lookupColumn(ExprNode node) throws ParserException {
         try {

core/src/test/java/com/nfsdb/ql/parser/JoinQueryTest.java

@@ -843,6 +843,19 @@ public class JoinQueryTest extends AbstractOptimiserTest {
                         " limit 10,15");
     }
 
+    @Test
+    public void testNullInsteadOfNaN() throws Exception {
+        assertThat("1406\tVQHYIIQL\tKJE\tnull\tDYQFLMPNGEJKKJCRCKNPUTHTVNYXM\tDFDISBFBRCCQDV\tXTGNJ\t2015-07-10T00:00:01.406Z\tNaN\tNaN\tNaN\t\t\tnull\n" +
+                        "1414\tDHMTF\tRTGV\tnull\tHMDJSBGPXQTKPGGWFSTJSKSZSBEPDVNMFEVEMQCOHDBK\tJKBVDSERXZ\tOEENNEBQQEMXD\t2015-07-10T00:00:01.414Z\tNaN\tNaN\tNaN\t\t\tnull\n" +
+                        "1422\tEKVFCZGGCKCHK\tEEGCRISJP\tnull\tILWBREVXDHHWPREIFCMLRXSWMFWEKIOTXUPRNGEPIJVNKTXHNKYITYG\tYYBJER\tCNSFFLTRY\t2015-07-10T00:00:01.422Z\tNaN\tNaN\tNaN\t\t\tnull\n" +
+                        "1523\tV\tODSBTX\tnull\tECUZSRJCTRJLH\tVBNHX\tZHEI\t2015-07-10T00:00:01.523Z\tNaN\tNaN\tNaN\t\t\tnull\n" +
+                        "1567\tBWPEIFNITZK\tBIJXCYTOHOQT\tnull\tYZMMSEZIPCOCZZUFYIVELTS\tFVPDDGSEK\tUN\t2015-07-10T00:00:01.567Z\tNaN\tNaN\tNaN\t\t\tnull\n",
+                "customers c" +
+                        " outer join orders o on c.customerId = o.customerId " +
+                        " where orderId = null" +
+                        " limit 10,15");
+    }
+
     @Test
     public void testNullSymbol() throws Exception {
         assertThat("",