diff --git a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcConnection.java b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcConnection.java
index d1b270d40..aab221e0b 100644
--- a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcConnection.java
+++ b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcConnection.java
@@ -61,15 +61,13 @@
  * @author H2 Group
  * @author zhh
  */
-// 只支持Java 1.7中的JDBC API
 public class JdbcConnection extends TraceObject implements Connection {
 
     private static boolean keepOpenStackTrace;
     private final String url;
     private final String user;
 
-    // ResultSet.HOLD_CURSORS_OVER_COMMIT
-    private int holdability = 1;
+    private int holdability = ResultSet.HOLD_CURSORS_OVER_COMMIT;
 
     private Session session;
     private Command commit, rollback;
@@ -100,7 +98,7 @@ public JdbcConnection(String url, Properties info) throws SQLException {
             // this will return an embedded or server connection
             session = new ClientSession(ci).connectEmbeddedOrServer();
             trace = session.getTrace();
-            int id = getNextId(TraceObject.CONNECTION);
+            int id = getNextTraceId(TraceObject.CONNECTION);
             setTrace(trace, TraceObject.CONNECTION, id);
             user = ci.getUserName();
             url = ci.getURL(); // 不含参数
@@ -123,7 +121,7 @@ public JdbcConnection(String url, Properties info) throws SQLException {
     public JdbcConnection(Session session, String user, String url) {
         this.session = session;
         trace = session.getTrace();
-        int id = getNextId(TraceObject.CONNECTION);
+        int id = getNextTraceId(TraceObject.CONNECTION);
         setTrace(trace, TraceObject.CONNECTION, id);
         this.user = user;
         this.url = url;
@@ -159,7 +157,7 @@ private void closeOld() {
     @Override
     public Statement createStatement() throws SQLException {
         try {
-            int id = getNextId(TraceObject.STATEMENT);
+            int id = getNextTraceId(TraceObject.STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("Statement", TraceObject.STATEMENT, id, "createStatement()");
             }
@@ -184,7 +182,7 @@ public Statement createStatement() throws SQLException {
     @Override
     public Statement createStatement(int resultSetType, int resultSetConcurrency) throws SQLException {
         try {
-            int id = getNextId(TraceObject.STATEMENT);
+            int id = getNextTraceId(TraceObject.STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("Statement", TraceObject.STATEMENT, id, "createStatement(" + resultSetType + ", "
                         + resultSetConcurrency + ")");
@@ -212,7 +210,7 @@ public Statement createStatement(int resultSetType, int resultSetConcurrency) th
     public Statement createStatement(int resultSetType, int resultSetConcurrency, int resultSetHoldability)
             throws SQLException {
         try {
-            int id = getNextId(TraceObject.STATEMENT);
+            int id = getNextTraceId(TraceObject.STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("Statement", TraceObject.STATEMENT, id, "createStatement(" + resultSetType + ", "
                         + resultSetConcurrency + ", " + resultSetHoldability + ")");
@@ -236,7 +234,7 @@ public Statement createStatement(int resultSetType, int resultSetConcurrency, in
     @Override
     public PreparedStatement prepareStatement(String sql) throws SQLException {
         try {
-            int id = getNextId(TraceObject.PREPARED_STATEMENT);
+            int id = getNextTraceId(TraceObject.PREPARED_STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("PreparedStatement", TraceObject.PREPARED_STATEMENT, id, "prepareStatement("
                         + quote(sql) + ")");
@@ -259,7 +257,7 @@ public PreparedStatement prepareStatement(String sql) throws SQLException {
      */
     PreparedStatement prepareAutoCloseStatement(String sql) throws SQLException {
         try {
-            int id = getNextId(TraceObject.PREPARED_STATEMENT);
+            int id = getNextTraceId(TraceObject.PREPARED_STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("PreparedStatement", TraceObject.PREPARED_STATEMENT, id, "prepareStatement("
                         + quote(sql) + ")");
@@ -282,7 +280,7 @@ PreparedStatement prepareAutoCloseStatement(String sql) throws SQLException {
     @Override
     public DatabaseMetaData getMetaData() throws SQLException {
         try {
-            int id = getNextId(TraceObject.DATABASE_META_DATA);
+            int id = getNextTraceId(TraceObject.DATABASE_META_DATA);
             if (isDebugEnabled()) {
                 debugCodeAssign("DatabaseMetaData", TraceObject.DATABASE_META_DATA, id, "getMetaData()");
             }
@@ -591,7 +589,7 @@ public void clearWarnings() throws SQLException {
     public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency)
             throws SQLException {
         try {
-            int id = getNextId(TraceObject.PREPARED_STATEMENT);
+            int id = getNextTraceId(TraceObject.PREPARED_STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("PreparedStatement", TraceObject.PREPARED_STATEMENT, id, "prepareStatement("
                         + quote(sql) + ", " + resultSetType + ", " + resultSetConcurrency + ")");
@@ -819,7 +817,7 @@ public void setTypeMap(Map<String, Class<?>> map) throws SQLException {
     @Override
     public CallableStatement prepareCall(String sql) throws SQLException {
         try {
-            int id = getNextId(TraceObject.CALLABLE_STATEMENT);
+            int id = getNextTraceId(TraceObject.CALLABLE_STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("CallableStatement", TraceObject.CALLABLE_STATEMENT, id, "prepareCall(" + quote(sql)
                         + ")");
@@ -848,7 +846,7 @@ public CallableStatement prepareCall(String sql) throws SQLException {
     @Override
     public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency) throws SQLException {
         try {
-            int id = getNextId(TraceObject.CALLABLE_STATEMENT);
+            int id = getNextTraceId(TraceObject.CALLABLE_STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("CallableStatement", TraceObject.CALLABLE_STATEMENT, id, "prepareCall(" + quote(sql)
                         + ", " + resultSetType + ", " + resultSetConcurrency + ")");
@@ -879,7 +877,7 @@ public CallableStatement prepareCall(String sql, int resultSetType, int resultSe
     public CallableStatement prepareCall(String sql, int resultSetType, int resultSetConcurrency,
             int resultSetHoldability) throws SQLException {
         try {
-            int id = getNextId(TraceObject.CALLABLE_STATEMENT);
+            int id = getNextTraceId(TraceObject.CALLABLE_STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("CallableStatement", TraceObject.CALLABLE_STATEMENT, id, "prepareCall(" + quote(sql)
                         + ", " + resultSetType + ", " + resultSetConcurrency + ", " + resultSetHoldability + ")");
@@ -902,7 +900,7 @@ public CallableStatement prepareCall(String sql, int resultSetType, int resultSe
     @Override
     public Savepoint setSavepoint() throws SQLException {
         try {
-            int id = getNextId(TraceObject.SAVEPOINT);
+            int id = getNextTraceId(TraceObject.SAVEPOINT);
             if (isDebugEnabled()) {
                 debugCodeAssign("Savepoint", TraceObject.SAVEPOINT, id, "setSavepoint()");
             }
@@ -926,7 +924,7 @@ public Savepoint setSavepoint() throws SQLException {
     @Override
     public Savepoint setSavepoint(String name) throws SQLException {
         try {
-            int id = getNextId(TraceObject.SAVEPOINT);
+            int id = getNextTraceId(TraceObject.SAVEPOINT);
             if (isDebugEnabled()) {
                 debugCodeAssign("Savepoint", TraceObject.SAVEPOINT, id, "setSavepoint(" + quote(name) + ")");
             }
@@ -996,7 +994,7 @@ private static JdbcSavepoint convertSavepoint(Savepoint savepoint) {
     public PreparedStatement prepareStatement(String sql, int resultSetType, int resultSetConcurrency,
             int resultSetHoldability) throws SQLException {
         try {
-            int id = getNextId(TraceObject.PREPARED_STATEMENT);
+            int id = getNextTraceId(TraceObject.PREPARED_STATEMENT);
             if (isDebugEnabled()) {
                 debugCodeAssign("PreparedStatement", TraceObject.PREPARED_STATEMENT, id, "prepareStatement("
                         + quote(sql) + ", " + resultSetType + ", " + resultSetConcurrency + ", " + resultSetHoldability
@@ -1399,7 +1397,7 @@ ResultSet getGeneratedKeys(JdbcStatement stat, int id) {
     @Override
     public Clob createClob() throws SQLException {
         try {
-            int id = getNextId(TraceObject.CLOB);
+            int id = getNextTraceId(TraceObject.CLOB);
             debugCodeAssign("Clob", TraceObject.CLOB, id, "createClob()");
             checkClosed();
             Value v = session.getDataHandler().getLobStorage()
@@ -1418,7 +1416,7 @@ public Clob createClob() throws SQLException {
     @Override
     public Blob createBlob() throws SQLException {
         try {
-            int id = getNextId(TraceObject.BLOB);
+            int id = getNextTraceId(TraceObject.BLOB);
             debugCodeAssign("Blob", TraceObject.BLOB, id, "createClob()");
             checkClosed();
             Value v = session.getDataHandler().getLobStorage()
@@ -1438,7 +1436,7 @@ public Blob createBlob() throws SQLException {
     @Override
     public NClob createNClob() throws SQLException {
         try {
-            int id = getNextId(TraceObject.CLOB);
+            int id = getNextTraceId(TraceObject.CLOB);
             debugCodeAssign("NClob", TraceObject.CLOB, id, "createNClob()");
             checkClosed();
             Value v = session.getDataHandler().getLobStorage()
@@ -1621,12 +1619,12 @@ Object convertToDefaultObject(Value v) {
         Object o;
         switch (v.getType()) {
         case Value.CLOB: {
-            int id = getNextId(TraceObject.CLOB);
+            int id = getNextTraceId(TraceObject.CLOB);
             o = new JdbcClob(this, v, id);
             break;
         }
         case Value.BLOB: {
-            int id = getNextId(TraceObject.BLOB);
+            int id = getNextTraceId(TraceObject.BLOB);
             o = new JdbcBlob(this, v, id);
             break;
         }
diff --git a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcDataSource.java b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcDataSource.java
index 797ec0c25..a165f8e33 100644
--- a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcDataSource.java
+++ b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcDataSource.java
@@ -77,7 +77,7 @@ public class JdbcDataSource extends TraceObject implements DataSource, Serializa
      */
     public JdbcDataSource() {
         initFactory();
-        int id = getNextId(TraceObject.DATA_SOURCE);
+        int id = getNextTraceId(TraceObject.DATA_SOURCE);
         setTrace(factory.getTrace(), TraceObject.DATA_SOURCE, id);
     }
 
diff --git a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcPreparedStatement.java b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcPreparedStatement.java
index bc1d5a4dc..47030aa4a 100644
--- a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcPreparedStatement.java
+++ b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcPreparedStatement.java
@@ -93,7 +93,7 @@ void setCachedColumnLabelMap(HashMap<String, Integer> cachedColumnLabelMap) {
     @Override
     public ResultSet executeQuery() throws SQLException {
         try {
-            int id = getNextId(TraceObject.RESULT_SET);
+            int id = getNextTraceId(TraceObject.RESULT_SET);
             if (isDebugEnabled()) {
                 debugCodeAssign("ResultSet", TraceObject.RESULT_SET, id, "executeQuery()");
             }
@@ -166,7 +166,7 @@ private int executeUpdateInternal() throws SQLException {
     @Override
     public boolean execute() throws SQLException {
         try {
-            int id = getNextId(TraceObject.RESULT_SET);
+            int id = getNextTraceId(TraceObject.RESULT_SET);
             if (isDebugEnabled()) {
                 debugCodeCall("execute");
             }
@@ -1037,7 +1037,7 @@ public ResultSetMetaData getMetaData() throws SQLException {
             if (result == null) {
                 return null;
             }
-            int id = getNextId(TraceObject.RESULT_SET_META_DATA);
+            int id = getNextTraceId(TraceObject.RESULT_SET_META_DATA);
             if (isDebugEnabled()) {
                 debugCodeAssign("ResultSetMetaData", TraceObject.RESULT_SET_META_DATA, id, "getMetaData()");
             }
@@ -1277,7 +1277,7 @@ public boolean execute(String sql, String[] columnNames) throws SQLException {
     @Override
     public ParameterMetaData getParameterMetaData() throws SQLException {
         try {
-            int id = getNextId(TraceObject.PARAMETER_META_DATA);
+            int id = getNextTraceId(TraceObject.PARAMETER_META_DATA);
             if (isDebugEnabled()) {
                 debugCodeAssign("ParameterMetaData", TraceObject.PARAMETER_META_DATA, id, "getParameterMetaData()");
             }
diff --git a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcResultSet.java b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcResultSet.java
index 281186808..904905cac 100644
--- a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcResultSet.java
+++ b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcResultSet.java
@@ -134,7 +134,7 @@ public boolean next() throws SQLException {
     @Override
     public ResultSetMetaData getMetaData() throws SQLException {
         try {
-            int id = getNextId(TraceObject.RESULT_SET_META_DATA);
+            int id = getNextTraceId(TraceObject.RESULT_SET_META_DATA);
             if (isDebugEnabled()) {
                 debugCodeAssign("ResultSetMetaData", TraceObject.RESULT_SET_META_DATA, id, "getMetaData()");
             }
@@ -991,7 +991,7 @@ public Timestamp getTimestamp(String columnLabel, Calendar calendar) throws SQLE
     @Override
     public Blob getBlob(int columnIndex) throws SQLException {
         try {
-            int id = getNextId(TraceObject.BLOB);
+            int id = getNextTraceId(TraceObject.BLOB);
             debugCodeAssign("Blob", TraceObject.BLOB, id, "getBlob(" + columnIndex + ")");
             Value v = get(columnIndex);
             return v == ValueNull.INSTANCE ? null : new JdbcBlob(conn, v, id);
@@ -1011,7 +1011,7 @@ public Blob getBlob(int columnIndex) throws SQLException {
     @Override
     public Blob getBlob(String columnLabel) throws SQLException {
         try {
-            int id = getNextId(TraceObject.BLOB);
+            int id = getNextTraceId(TraceObject.BLOB);
             debugCodeAssign("Blob", TraceObject.BLOB, id, "getBlob(" + quote(columnLabel) + ")");
             Value v = get(columnLabel);
             return v == ValueNull.INSTANCE ? null : new JdbcBlob(conn, v, id);
@@ -1103,7 +1103,7 @@ public InputStream getBinaryStream(String columnLabel) throws SQLException {
     @Override
     public Clob getClob(int columnIndex) throws SQLException {
         try {
-            int id = getNextId(TraceObject.CLOB);
+            int id = getNextTraceId(TraceObject.CLOB);
             debugCodeAssign("Clob", TraceObject.CLOB, id, "getClob(" + columnIndex + ")");
             Value v = get(columnIndex);
             return v == ValueNull.INSTANCE ? null : new JdbcClob(conn, v, id);
@@ -1123,7 +1123,7 @@ public Clob getClob(int columnIndex) throws SQLException {
     @Override
     public Clob getClob(String columnLabel) throws SQLException {
         try {
-            int id = getNextId(TraceObject.CLOB);
+            int id = getNextTraceId(TraceObject.CLOB);
             debugCodeAssign("Clob", TraceObject.CLOB, id, "getClob(" + quote(columnLabel) + ")");
             Value v = get(columnLabel);
             return v == ValueNull.INSTANCE ? null : new JdbcClob(conn, v, id);
@@ -1143,7 +1143,7 @@ public Clob getClob(String columnLabel) throws SQLException {
     @Override
     public Array getArray(int columnIndex) throws SQLException {
         try {
-            int id = getNextId(TraceObject.ARRAY);
+            int id = getNextTraceId(TraceObject.ARRAY);
             debugCodeAssign("Clob", TraceObject.ARRAY, id, "getArray(" + columnIndex + ")");
             Value v = get(columnIndex);
             return v == ValueNull.INSTANCE ? null : new JdbcArray(conn, v, id);
@@ -1163,7 +1163,7 @@ public Array getArray(int columnIndex) throws SQLException {
     @Override
     public Array getArray(String columnLabel) throws SQLException {
         try {
-            int id = getNextId(TraceObject.ARRAY);
+            int id = getNextTraceId(TraceObject.ARRAY);
             debugCodeAssign("Clob", TraceObject.ARRAY, id, "getArray(" + quote(columnLabel) + ")");
             Value v = get(columnLabel);
             return v == ValueNull.INSTANCE ? null : new JdbcArray(conn, v, id);
@@ -3370,7 +3370,7 @@ public void updateNClob(String columnLabel, NClob x) throws SQLException {
     @Override
     public NClob getNClob(int columnIndex) throws SQLException {
         try {
-            int id = getNextId(TraceObject.CLOB);
+            int id = getNextTraceId(TraceObject.CLOB);
             debugCodeAssign("NClob", TraceObject.CLOB, id, "getNClob(" + columnIndex + ")");
             Value v = get(columnIndex);
             return v == ValueNull.INSTANCE ? null : new JdbcClob(conn, v, id);
@@ -3390,7 +3390,7 @@ public NClob getNClob(int columnIndex) throws SQLException {
     @Override
     public NClob getNClob(String columnLabel) throws SQLException {
         try {
-            int id = getNextId(TraceObject.CLOB);
+            int id = getNextTraceId(TraceObject.CLOB);
             debugCodeAssign("NClob", TraceObject.CLOB, id, "getNClob(" + columnLabel + ")");
             Value v = get(columnLabel);
             return v == ValueNull.INSTANCE ? null : new JdbcClob(conn, v, id);
diff --git a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcStatement.java b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcStatement.java
index 16098ef95..6d880da58 100644
--- a/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcStatement.java
+++ b/lealone-client/src/main/java/org/lealone/client/jdbc/JdbcStatement.java
@@ -66,7 +66,7 @@ public class JdbcStatement extends TraceObject implements Statement {
     @Override
     public ResultSet executeQuery(String sql) throws SQLException {
         try {
-            int id = getNextId(TraceObject.RESULT_SET);
+            int id = getNextTraceId(TraceObject.RESULT_SET);
             if (isDebugEnabled()) {
                 debugCodeAssign("ResultSet", TraceObject.RESULT_SET, id, "executeQuery(" + quote(sql) + ")");
             }
@@ -179,7 +179,7 @@ private boolean executeInternal(String sql) throws SQLException {
                 }
             }
         }
-        int id = getNextId(TraceObject.RESULT_SET);
+        int id = getNextTraceId(TraceObject.RESULT_SET);
         checkClosed();
         closeOldResultSet();
         sql = JdbcConnection.translateSQL(sql, escapeProcessing);
@@ -714,7 +714,7 @@ public int[] executeBatch() throws SQLException {
     @Override
     public ResultSet getGeneratedKeys() throws SQLException {
         try {
-            int id = getNextId(TraceObject.RESULT_SET);
+            int id = getNextTraceId(TraceObject.RESULT_SET);
             if (isDebugEnabled()) {
                 debugCodeAssign("ResultSet", TraceObject.RESULT_SET, id, "getGeneratedKeys()");
             }
diff --git a/lealone-common/src/main/java/org/lealone/common/trace/TraceObject.java b/lealone-common/src/main/java/org/lealone/common/trace/TraceObject.java
index e15222278..9557def61 100644
--- a/lealone-common/src/main/java/org/lealone/common/trace/TraceObject.java
+++ b/lealone-common/src/main/java/org/lealone/common/trace/TraceObject.java
@@ -131,7 +131,7 @@ public String getTraceObjectName() {
      * @param type the object type
      * @return the new trace object id
      */
-    protected static int getNextId(int type) {
+    protected static int getNextTraceId(int type) {
         return ID[type]++;
     }