http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4263113 to see the bug.
DriverManager is very slow opening connections.
1) Compile this the DriverManager.java obviously place it under a java/sql folder.
DriverManager.java for JDK 1.5
DriverManager.java for JDK 1.4
1a) javac java/sql/DriverManager.java
2) This will generate DriverInfo.class and DriverManager.class
3) Find the archive in your jdk containing the original DriverManager.java and replace inside the two classes
For example in my system the archive is C:\oracle\jdevstudio1013\jdk\jre\lib\rt.jar
Hope this help!