So one fine evening, there was a scheduled maintenance, and one of the databases didn’t shutdown cleanly (thanks to mis-configured Windows services, if I recall correctly). Consequently, the database crashed and later didn’t come back up.When I looked at it in the morning, the error message rang a bell: “Datafile 1 needs media recovery” in combination with the request for very old archivelogs.The moral of the story: do not leave datafiles in backup mode. If you use hot backups outside of RMAN, such as snapshot technologies, take care to implement monitoring so that the database doesn’t stay in backup mode for much time.
Sometimes there is a desperate need to change hostnames for one or all nodes of an Oracle RAC cluster. However, this operation is not officially supported. One way to do it is to remove a node from a cluster, change its hostname, and then add it back to the cluster as a new node. If you are brave enough, there is another way to do this. Find out here.
Congratulations to Christo, Senior (and stylish!) DBA for The Pythian Group, on his spread in the July/August issue of Oracle Magazine, which you can download! Just jump straight to page 41 (not page 3), feast your eyes and hear what he has to say about Oracle Enterprise Manager! Here’s a sneak preview!
I came across Oracle Coherence today. Seems like this is another approach to clustering than Oracle RAC. Seems like this is a way to scale middle tiers that require shared data without actually using the central database for that. On the other hand, looks like a clustering framework with rules defined by developers as opposed to Oracle RAC that is designed and built to be a black box delivering database services. Has anyone (yeah, I’m asking developers reading the blog) played with it and knows how it feels?
Pawel Barut has published the 48th edition of Log Buffer, the weekly review of database blogs, on his blog, Software Engineer Thoughts.
A few days ago, I did a short post about the start of the Miracle Scotland Database Forum 2007. I decided to wait until getting back home to complete a full-blown description of the event. I should warn you, this will be quite lengthy, so draw a deep breath.
A short post to draw your attention to this article by Kevin Burton titled “MySQL and the Death of Raid”. Although it’s written from the MySQL point of view, he does bring up some interesting points on the advantages of what he calls a “RAISe” or Redundant Array of Independent Servers” architecture (actually I coined the RAISe acronym just now :-) ) over the traditional RAID approach of hardening the availability and performance of your disk. Take a look and let me know what you think.
Ronald Bradford has published the 47th edition of Log Buffer, the weekly review of database blogs, on Technical Notes and Articles of Interest.
So you have followed the recipes to create a standby database, setup the database to switch logs automatically, and now, as with any good database, the space required to support the application grows and grows and grows. Eventually, using your monitoring software (in my case, Pythian’s avail or dailies), you get an alert suggesting that you will need to add additional space. In this case you are going to add a datafile to a tablespace, or add a brand new tablespace.
Yesterday was the opening and I should say it was great — nice tour on the Whiskey Heritage Center and couple interesting and humorous sessions delivered by Jonathan Lewis and Graham Wood combined with whiskey tasting. The evening obviously continued after that but you can assume that anyway if you know what I’m talking about.