Of all the frustrating, partially-completed features Oracle has released, this is the most frustrating. Did I mention this frustrating feature is frustrating when you get bitten by it?What am I referring to? FLASHBACK QUERY on a table that lives in a database with a large UNDO_RETENTION specified with lots and lots of UNDO_TABLESPACE space. Why is this behaving this way? Silly me, I really should read Oracle docs more carefully.Here’s what they say at Managing Undo for Your Database…There you have it folks. Please don’t get bitten with this the way I did.Read More >
I just installed a copy of the titular distro last night and have been playing with it a bit. So far it’s been less trouble than I would have expected from a first beta, and runs well. Get Kubuntu 9.10 Karmic Koala beta 1 here. A word to the wise, this is beta software and not yet ready for prime time.Read More >
So there I am, on my morning bus ride, reading my copy of ‘The Definitive Guide to Catalyst’, unaware of the surprise that is about to fall on me like a rabid koala bear…The script in the book is a wee bit different and has been improved upon, but its origin is unmistakable. Somehow, unexpectedly, a hack of mine found its way into publication. Fame, glory, and page 293 of the Catalyst book, I can finally claim ’em all as rightfully mine! But, serendipitous glee aside, three important lessons lie in this little story.Read More >
Recently I was looking into a long-running statement and noticed a curious thing. One moment, I had just over 4 billion buffer gets, and the next I had around 2 million. Beware that if you have had a statement running for some time, you cannot necessarily rely on the buffer_gets column in v$sql—it may be that it has run over the limit, been recycled, and is counting from zero again.Read More >
Gowlings hosted a debate on open source licenses organized by the Free and Open Source Software Learning Centre (FOSSLC). The debate was conducted between the proponents of three major Open Source licenses: Mike Milinkovich for the EPL, Matt Asay for the GPL, and David Maxwell for the BSD license. Videos of the event are available on the FOSSLC site.Read More >
Considering my recent update to Ubuntu 9.10, I decided to have another go at getting TOra up and running. This time I am tackling a 64-bit system rather than the 32-bit “Hardy Heron” I had done previously. On my way, I found some odd issues that I will describe here. All in all, it was a good few hours of cobbling together the pieces I needed to proudly present to you . . .Read More >
Recently while we were building a slave with a newer version of MySQL 5.1 from an InnoDB Hot backup an error occurred The problem is, in MySQL 5.1, it is possible to log the slow query log and general log to tables in the mysql schema. These tables are created by default as CSV tables for performance reasons, even if MySQL is set not to log to tables. CSV tables, however, are not copied as part of the InnoDB Hot Backup process, creating this error. Here is the fix to get the slave workingRead More >
This blog post was inspired by a recent report of a Database Analyst at American Express stealing Credit Card data. It’s amazing how many companies still follow a mainly “perimeter security” approach when it comes to controlling access to sensitive information—their focus is on network security using firewalls, advanced authentication options, and so on. Even with such measures, it’s very common to setup strong barriers to the outside world but very little by way of internal limits; most internal people have some level of access to servers that store and process sensitive data.Read More >
OpenSQL Camp will take place Saturday 22nd and Sunday 23rd of August, in St. Augustin, Germany, so it could do for a nice August getaway to Germany. It’s not really the biggest of cities, but then again, that is part of the charm, going to some small city and learning more about databases.
In case you do happen to be curious, feel free to check out the list of proposed sessions, although it is not complete, it does give a overview of what to expect.
Recently, I tested a switchover on Oracle 11g SE1. As you know, Oracle Database Standard Edition One—as well as Standard Edition—does not have the Data Guard feature. Therefore, I had to do everything manually. The whole process took less than 15 minutes. This includes less than five minutes of full downtime to restart the database in READ-ONLY mode, and less than 10 minutes of READ-ONLY downtime. Here’s what I had.Read More >