Fix bug in MVStore when creating lots of temporary tables, where we could run…

Fix bug in MVStore when creating lots of temporary tables, where we could run out of transaction IDs.    

h2/src/docsrc/html/changelog.html

@@ -57,6 +57,8 @@ Change Log
     so that it was effectly 1024 times smaller than it should be.
 </li><li>Concurrent CREATE TABLE... IF NOT EXISTS in the presence of MULTI_THREAD=TRUE could
     throw an exception.
+</li><li>Fix bug in MVStore when creating lots of temporary tables, where we could run out of
+    transaction IDs.    
 </li></ul>
 
 <h2>Version 1.4.186 Beta (2015-03-02)</h2>

h2/src/main/org/h2/mvstore/db/MVPrimaryIndex.java

@@ -71,8 +71,9 @@ public class MVPrimaryIndex extends BaseIndex {
         ValueDataType valueType = new ValueDataType(db.getCompareMode(), db,
                 sortTypes);
         mapName = "table." + getId();
-        dataMap = mvTable.getTransaction(null).openMap(mapName, keyType,
-                valueType);
+        Transaction t = mvTable.getTransaction(null); 
+        dataMap = t.openMap(mapName, keyType, valueType);
+        t.commit();
         if (!table.isPersistData()) {
             dataMap.map.setVolatile(true);
         }

h2/src/main/org/h2/mvstore/db/MVSecondaryIndex.java

@@ -68,8 +68,9 @@ public class MVSecondaryIndex extends BaseIndex implements MVIndex {
         ValueDataType keyType = new ValueDataType(
                 db.getCompareMode(), db, sortTypes);
         ValueDataType valueType = new ValueDataType(null, null, null);
-        dataMap = mvTable.getTransaction(null).openMap(
-                mapName, keyType, valueType);
+        Transaction t = mvTable.getTransaction(null); 
+        dataMap = t.openMap(mapName, keyType, valueType);
+        t.commit();
         if (!keyType.equals(dataMap.getKeyType())) {
             throw DbException.throwInternalError("Incompatible key type");
         }

h2/src/main/org/h2/mvstore/db/MVSpatialIndex.java

@@ -102,7 +102,9 @@ public class MVSpatialIndex extends BaseIndex implements SpatialIndex, MVIndex {
                 new MVRTreeMap.Builder<VersionedValue>().
                 valueType(valueType);
         spatialMap = db.getMvStore().getStore().openMap(mapName, mapBuilder);
-        dataMap = mvTable.getTransaction(null).openMap(spatialMap);
+        Transaction t = mvTable.getTransaction(null); 
+        dataMap = t.openMap(spatialMap);
+        t.commit();
     }
 
     @Override

h2/src/test/org/h2/test/db/TestTempTables.java

@@ -45,6 +45,7 @@ public class TestTempTables extends TestBase {
         testIndexes(c1, c2);
         c1.close();
         c2.close();
+        testLotsOfTables();
         deleteDb("tempTables");
     }
 
@@ -293,4 +294,16 @@ public class TestTempTables extends TestBase {
                 executeQuery("select * from test_temp");
     }
 
+    /** There was a bug where creating lots of tables would overflow the transaction table in the MVStore
+     */
+    private void testLotsOfTables() throws SQLException {
+        deleteDb("tempTables");
+        Connection conn = getConnection("tempTables");
+        Statement stat = conn.createStatement();
+        for (int i = 0; i < 100000; i++) {
+            stat.executeUpdate("create local temporary table t(id int)");
+            stat.executeUpdate("drop table t");
+        }
+        conn.close();
+    }
 }