Circular dependency detected while autoloading constant

I recently ran into this frustrating and intermittent error in Ruby on Rails 4 (JRuby, actually): Circular dependency detected while autoloading constant Googling turned up several articles advising one to abide by the Rails conventions, but that was not the issue. The application I'm writing uses background threads. The problem shows up when trying to … Continue reading Circular dependency detected while autoloading constant

Userscript to make banning MediaWiki spammers easier

Somehow, I've come to be responsible for administering two MediaWiki-powered wikis. The main burden is having to ban spammers, which sometimes sign up in batches of 20 at a time. To help with process, I've put together the following browser userscript. On Firefox, you can easily set it up using the Greasemonkey extension. Opera and … Continue reading Userscript to make banning MediaWiki spammers easier

DB2 Express-C 9.7.5 released with Oracle compatibility

My team just put out DB2 Express-C 9.7.5. The big new feature is Oracle compatibility, which is now available in the free edition. It includes PL/SQL, CLPPlus, and other related things. DB2 Express-C is a free database. It's fairly straightforward to install on your own machine or deploy on a public cloud like Amazon EC2 … Continue reading DB2 Express-C 9.7.5 released with Oracle compatibility

SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing

I've written about issues related to "SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing" before, but I thought I'd add a few short notes. Your machine needs to be able to ping itself. If it can't ping itself, it can't DB2 itself either. The output of hostname, db2set -all, and cat … Continue reading SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing

Webinar on private clouds, including stuff I’ve been working on

There's a DB2 Chat with the Lab on Wednesday next week which will cover, among other things, the DB2 images I've developed for IBM Workload Deployer over this past while. I recommend checking it out, as the speakers know their stuff and this is a pretty cool product. Easily Deploy Database Workloads on Private Clouds … Continue reading Webinar on private clouds, including stuff I’ve been working on

Reduce your stress by disabling notifiers, toasts, and every sort of popup

A month ago, I disabled email notification in my Gmail notifier before doing a presentation and neglected to turn it back on later. It took me a long time to notice the lack of notifications. What I did notice was a reduced level of stress. I was able to effectively concentrate on a single task … Continue reading Reduce your stress by disabling notifiers, toasts, and every sort of popup

Find a list of views marked inoperative

When you drop and recreate a table, DB2 marks any views that query it inoperative. You will get the following error message if you try to query one of them: View or materialized query table "TRENDADM.IWM_CONVERSION"  cannot be used because it has been marked inoperative..  SQLCODE=-575, SQLSTATE=51024, DRIVER=3.61.65 This has changed somewhat in DB2 9.7 … Continue reading Find a list of views marked inoperative