The Pros and Cons of Type 1 JDBC driver

While writing JDBC applications, developers generally start with JDBC-ODBCBridge to connect to databases. But when an application reaches some advanced stage, for example, when it needs to support multithreading, the JDBC-ODBCBridge poses a few problems. So, the need arises for a robust JDBC driver. In that case, the type of driver depends on quite a few parameters: whether the application is Internet or intranet based, whether it needs to support heterogeneous databases, the number of concurrent users, and so on.

JDBC drivers are divided into four types or levels. Each type defines a JDBC driver implementation with increasingly higher levels of platform independence, performance, and deployment administration. The four types are:

Type 1: JDBC-ODBC Bridge

Type 2: Native-API/partly Java driver

Type 3: Net-protocol/all-Java driver

Type 4: Native-protocol/all-Java driver

The type 1 driver, JDBC-ODBC Bridge, translates all JDBC calls into ODBC (Open DataBase Connectivity) calls and sends them to the ODBC driver. As such, the ODBC driver, as well as, in many cases, the client database code, must be present on the client machine. Figure 1 shows a typical JDBC-ODBC Bridge environment.

The JDBC-ODBC Bridge allows access to almost any database, since the database's ODBC drivers are already available. Type 1 drivers may be useful for those web development companies that have an ODBC driver already installed on client machines. From the other side, the performance is degraded since the JDBC call goes through the bridge to the ODBC driver, then to the native database connectivity interface. The result comes back through the reverse process. Considering the performance issue, type 1 drivers may not be suitable for large-scale web development applications. The ODBC driver and native connectivity interface must already be installed on the client machine. Thus any advantage of using Java applets in an intranet environment is lost, since the deployment problems of traditional applications remain.