"max.andersen(a)jboss.com" wrote : if you are using hsql in-memory then only one process can access the database at one time. | | you should at least use a hsql server if you want concurrent access. Ok, I *finally* ran two HQL queries in the HQL editor successfully for the booking project using HSQLDB: "from User" and "from Hotel". I'm not sure how/why that lock error was happening but now I actually am able to run simultaneous HQL queries from JBDS and from HSQL DB mgr swing app. So now I know that I should be able to get my seam-gen'd project to work with HQL Editor as well b/c the booking project has the same project skeleton/structure. I had to learn how HSQLDB works and load/creates tables on startup, etc. but this was a good POC success for my scenario... View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4217200#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...