General bug fixing for Apache Derby

by Abhinav Gupta for Apache Software Foundation

Apache Derby an Apache DB subproject, is a relational database implemented entirely in Java. Over the years, Derby has been an active Apache project with many contributors and committers, still a significant number of challenging and interesting bugs remain in the Derby source code. The objective of this project is to resolve some of the challenging bugs currently present in the source code and contribute towards a more stable version of Apache Derby.