What is the best way to implement connection pooling in hsqldb, without compromising on the speed?
Hibernate gets connections from a DataSource, uses them and closes them. You need a connection pool or it will be very inefficient, consuming a lot of resources both on your app and on the DBMS, regardless of the database server you use.
You should try out commons-dbcp from Apache-Jakarta, it's very efficient and really simple to set up. It depends on commons-pool.
You just define a BasicDataSource with DBCP and it will manage the connections from whatever JDBC driver you tell it to use. It has connection validation and lots of other stuff.
Of, if you're writing a web app, configure a connection pool on the container you will be using and use that, instead of defining your own pool.