Critical to recovering a database, but largely invisible, it is a good idea to understand the recovery history file, what it contains, and how to access it.
IBM released fix pack 3, mod pack 3 for Db2 11.1 earlier this year, and there was a high-severity problem in the initial version of that fix pack. IBM fixed the problem and re-released the fix pack within about a day, but the bug was reported far and wide, while I’m not sure the resolution of the bug was, so I thought I’d cover it quickly.
What is an index in an RDBMS(Relational DataBase Management System), and what are the benefits and drawbacks of using an index? Why don’t we index everything? How is a clustered index different? Indexes are powerful tools in relational databases. They can speed up performance of queries exponentially, but they can also slow down inserts, updates, and deletes. Let’s take a look at indexing and why it is so important to RDBMS performance, good or bad.
Database servers these days sometimes have a profusion of IP Addresses. IP V4, V6, management networks, and Virtual IP addresses all add to the ways applications connect in to a database server. I ran into an issue recently where I really needed to know what IP address was being used by an application, and thought I would share what I learned.
One of the awesome things about running scripts locally on a DB2 server is that if they’re run as a privileged user, you do not have to specify the password. This makes for easier scripting without storing or encrypting passwords. When I first connected to a database with PowerShell, it took me a bit to figure out how to do the password-less local connection, so I thought I would share.
I have worked with DB2 on Windows on and off over the years and have largely not enjoyed it all that much. Most likely because the vast majority of my time is spent on UNIX and Linux systems, so when I end up at a windows command line, my fingers type things like “ls” and “grep” before I can even stop them. I think this is a common condition for DB2 consultants and DBAs – most of us spend the majority of our time on Linux or UNIX or even both and then have to jump into a Windows system and still be proficient.
I am at this point an expert on DB2, and on the aspects of DB2 that interact with Commerce, and frequently train clients and new DBAs on how to do what I do, so it's time to share.