SHUTDOWN DEFAG didn't defragment the database completely if there was a unique…

SHUTDOWN DEFAG didn't defragment the database completely if there was a unique hash index for a memory table.

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

@@ -328,4 +328,8 @@ public abstract class BaseIndex extends SchemaObjectBase implements Index {
         return false;
     }
 
+    public boolean canScan() {
+        return true;
+    }
+
 }

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

@@ -94,4 +94,8 @@ public class FunctionIndex extends BaseIndex {
         return "function";
     }
 
+    public boolean canScan() {
+        return false;
+    }
+
 }

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

@@ -116,4 +116,8 @@ public class HashIndex extends BaseIndex {
         throw DbException.getUnsupportedException("HASH");
     }
 
+    public boolean canScan() {
+        return false;
+    }
+
 }

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

@@ -226,4 +226,11 @@ public interface Index extends SchemaObject {
      */
     boolean isRowIdIndex();
 
+    /**
+     * Can this index iterate over all rows?
+     *
+     * @return true if it can
+     */
+    boolean canScan();
+
 }

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

@@ -318,4 +318,8 @@ public class MultiVersionIndex implements Index {
         return base.isRowIdIndex() && delta.isRowIdIndex();
     }
 
+    public boolean canScan() {
+        return base.canScan();
+    }
+
 }

h2/src/main/org/h2/store/PageStore.java

@@ -529,7 +529,7 @@ public class PageStore implements CacheWriter {
                         cursor.get();
                     }
                     for (Index index : table.getIndexes()) {
-                        if (index != scanIndex) {
+                        if (index != scanIndex && index.canScan()) {
                             cursor = index.find(s, null, null);
                             while (cursor.next()) {
                                 // the data is already read