I am wondering if there are examples of open source apps that are written in stored procedures? I read a lot about them in textbooks and would like to see how they are used in practice beyond implementing simple functionalities. One example that I found is the DBT benchmark implementations (http://sourceforge.net/apps/mediawiki/osdldbt) using stored procedures. If there are other similar applications I'd love to learn about them.
@a_horse_with_no_name: thanks for your pointer. Apps like LedgerSMB that makes heavy uses of stored procedures are exactly those that I am looking for. If there are other similar ones please let me know.