optimized for oracle

src/main/java/com/alibaba/druid/pool/DruidDataSource.java

@@ -290,6 +290,10 @@ public class DruidDataSource extends DruidAbstractDataSource implements DruidDat
 
             if ("oracle".equals(this.dbType)) {
                 isOracle = true;
+                
+                if (driver.getMajorVersion() < 10) {
+                    throw new SQLException("not support oracle driver " + driver.getMajorVersion() + "." + driver.getMinorVersion());
+                }
             }
 
             String realDriverClassName = driver.getClass().getName();

src/main/java/com/alibaba/druid/pool/OracleUtils.java

@@ -5,7 +5,7 @@ import java.sql.PreparedStatement;
 import java.sql.SQLException;
 
 import oracle.jdbc.OracleConnection;
-import oracle.jdbc.driver.OracleStatement;
+import oracle.jdbc.OracleStatement;
 
 public class OracleUtils {
 
@@ -30,11 +30,17 @@ public class OracleUtils {
     }
 
     public static int getDefaultRowPrefetch(Connection conn, int value) throws SQLException {
-        if (conn instanceof OracleConnection) {
-            OracleConnection oracleConn = (OracleConnection) conn;
-            return oracleConn.getDefaultRowPrefetch();
-        }
+        OracleConnection oracleConn = conn.unwrap(OracleConnection.class);
+        return oracleConn.getDefaultRowPrefetch();
+    }
 
-        return -1;
+    public static void cancel(Connection conn) throws SQLException {
+        OracleConnection oracleConn = conn.unwrap(OracleConnection.class);
+        oracleConn.cancel();
+    }
+    
+    public static void pingDatabase(Connection conn) throws SQLException {
+        OracleConnection oracleConn = conn.unwrap(OracleConnection.class);
+        oracleConn.pingDatabase();
     }
 }

src/main/java/com/alibaba/druid/pool/PoolablePreparedStatement.java

@@ -173,7 +173,7 @@ public class PoolablePreparedStatement extends PoolableStatement implements Prep
         incrementExecuteCount();
         transactionRecord(sql);
 
-        oracleSetRowPrefetch();
+        // oracleSetRowPrefetch();
 
         try {
             ResultSet rs = stmt.executeQuery();
@@ -429,7 +429,7 @@ public class PoolablePreparedStatement extends PoolableStatement implements Prep
         incrementExecuteCount();
         transactionRecord(sql);
 
-        oracleSetRowPrefetch();
+        // oracleSetRowPrefetch();
 
         try {
             return stmt.execute();
@@ -438,7 +438,7 @@ public class PoolablePreparedStatement extends PoolableStatement implements Prep
         }
     }
 
-    private void oracleSetRowPrefetch() throws SQLException {
+    protected void oracleSetRowPrefetch() throws SQLException {
         if (!conn.isOracle()) {
             return;
         }
@@ -446,7 +446,7 @@ public class PoolablePreparedStatement extends PoolableStatement implements Prep
         if (holder.getHitCount() == 0) {
             return;
         }
-
+        
         int fetchRowPeak = holder.getFetchRowPeak();
 
         if (fetchRowPeak < 0) {