Overview

Database connection pools have been added to the Xalan SQL Extension for two reasons.

1. A performance enhancement where consecutive transformation can reused databse connections without reallocating resources from the JDBC Driver.
2. A method to share databse connections created outside the scope of the Xalan XSLT process with the stylesheets that use the SQL extensions

Requirments

Named Connection Pools

Connection Pools will be refered to by name to provide a linkage to connection pools created outside the scope of the Xalan Processor. Named Connection Pools will also provide a mechinsim to support non-native connection used in JDBC 1.0 and JNDI references in JDBC 2.0

Backwards Compatibility

If the existing connection mechinsim is used (constructors in XConnection), crreate a connection pool on its behalf. The name of the connecton pool will be the concatenation of the Driver name, DB URL, User name and password.

Connection Pool Wrapppers

Implement a connection pool interface that defines the required beahvoiur for connection pools. This interface will be used to adapt other connection mechinsims to the Xalan SQL Extensions

Minimal Dependancies

The SQL Extension will implement a minimal default connection pool mechinism. This will reduce the dependancy of third party libraries to build and use the Xalan SQL Processor. Other wrappers can be written to adapt third party connection pools to the processor. A sample of the Apache Turbine project is planned as a sample for the project.

Examples of Use

• Establishing a basic connection

Some code text
• Establishing a connection by suppliying the connection information in the XML

Some code text
• Using a connecction that has been established outside the Xalan Processor

Some code text

SQL Results

Error Control