Mysql: the definition of table prevents operation … on table

This is a tricky one affecting MySql table updates which have views. Documentation about this error actually explains the cause, but doesn't connect the dots. I have a view V on table T and want to delete some rows from T. That works fine as long as the DELETE statement doesn't involve the view, so … Continue reading Mysql: the definition of table prevents operation … on table →

logging container-managed datasource jdbc with log4jdbc

In my new 'old' project which I just inherited there is - once more - Hibernate and plain JDBC access to a database, happily mixed. Hibernate logs SQL nicely, but that leaves out whatever datbase access the rest of the application is performing. I found log4jdbc very convenient which allows fain-grained logging over every interaction … Continue reading logging container-managed datasource jdbc with log4jdbc →

JPA and postgres transaction isolation

The short story: the default Postgres transaction isolation level can lead to trouble in a web application. I'm showing here a way to change it in a Spring/JPA application. The long story: One of the applications I worked recently on consists of a rich client which issues an HTTP request for every little thing it … Continue reading JPA and postgres transaction isolation →

ORA-12519 connection errors and JUnit tests

In my current project we are running hundreds of JUnit tests which load a Spring application context, a Hibernate session factory and a c3p0 pool. The entire suite runs fine everywhere except a single machine where some tests will occasionally fail with a "ORA-12519, TNS:no appropriate service handler found" on an Oracle XE. The cause[1,2] … Continue reading ORA-12519 connection errors and JUnit tests →