I blogged a little while ago on how to create a basic sandbox VM for DB2. Since I’m a big fan of separating filesystems properly, I needed to learn how to add another disk and another filesystem to my sandbox VMs.
I’m a control freak. I think that control freaks tend to make good DBAs as long as they don’t take it too far. My position for years has been that I would rather control my runstats, reorgs, and backups directly than trust DB2’s automatic facilities. But I also try to keep an open mind. That means that every so often I have to give the new stuff a chance. This blog entry is about me giving automatic maintenance a try. I am NOT recommending it yet, but here’s how I approached it and what I saw.
I’ve played with the clpplus at least once before, but have generally thought of it as a tool created to satisfy those coming from Oracle and looking for Oracle-like features. One of the features I actually liked about Oracle in the class and certification tests that I took for it was the ability to specify values for an SQL statement stored in a file on execution. When I lamented the fact that DB2 doesn’t have this feature on twitter, @idbjorh was quick to remind me that such functionality is indeed available using CLPPLUS.
GENERATED ALWAYS can be a blessing or a curse. I’m not talking about identity columns here, but about creating a column that is actually a duplicate of some part of the data to boost performance. Sure, in 10.5 we can do indexes on expressions, but for some clients I have trouble just getting them to go to a supported level, much less the latest and greatest. There are still some cases where I use this trick, though I analyze the situation thoroughly before using it.
DB2 10.1 introduced a new feature commonly called RCAC (Row and Column Access Control) or FGAC(Fine-Grained Access Control). This is a bit less labor intensive to support than LBAC (Label Based Access Control), and solves some of the problems with LBAC. It allows a finer level of access control than the standard DB2 permissions scheme.
I’m always keeping an eye on Twitter to catch interesting bits of news, and that includes watching cross platform information. I find it fascinating to compare DB2 to other RDMBSes, and saw a great article from Use the Index, Luke (fabulous name!) – Seven Surprising Findings About DB2. I’d recommend reading it.
I have been playing a fair amount lately with clustering indexes and have been rehashing my views on reorging tables on an index. This is still a work in progress, but thought I’d share some details and see if others out there have any thoughts to share with me and others on it.
I have not made extensive use of the HADR Tools that IBM offers in the past. Most of my HADR setups to date have either been same-data-center using NEARSYNC or have used ASYNC to copy data between data centers. I haven’t had much cause to tweak my network settings or change my SYNCMODE settings based on hardware/networking.
Sometimes you just have to think out of the box. Sometimes there isn’t an answer on google. Sometimes you have to bend the laws of physics to get the answer. Sometimes you get lucky.
We interrupt your regular programming for a quick announcement.
This article is based off the “DB2 v10.1 – Row and Column Access Control (Column Masking)” presentation for the DB2 Night Show (Episode #128) – DB2’s Got Talent competition held on Friday, March 7th at 11am EST. Progression within the competition is based solely on audience voting. So if you found this useful, want to see more like this, and don’t want to see a grown man cry – please vote for Mike Krafick based on the article or on the DB2 Night Show replay. You will have one week from the original air date to vote.