Category: Experiments

6

Giving Automatic Maintenance a Fair Try

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...

sqlplus 1

Playing With CLPPLUS

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...

7

Adding a GENERATED ALWAYS Column to a Table

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,...

3

Customizing MONREPORT … or not

If you’re not familiar with MONREPORT, see my DB2 Basics entry on MONREPORT first. Most of the references I’ve seen to customizing the MONREPORT module basically say “get the code out of the database, modify it, and deploy it”. (see IBM DB2 Knowledge Center Entry on Customizing the MONREPORT module reports) I have found this rather frustrating when I’ve run...

2

DB2 Fine-Grained and Row Access Control (FGAC/RCAC)

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. RCAC consists of two major...

2

DB2 Explain Output in Another Format

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. One of the things that stood out most...

5

Clustering a Table on an Index

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. Clustering a Table on an Index I’ve...

1

HADR Tools: the HADR Simulator

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. However, I have...