A hub for sharing relational database knowledge and experimentation
It is significantly easier to implement high availability at other levels than it is at the database level. Often the database server is one of the more powerful servers in an environment, and without some fancy footwork there can be only one live copy of data.… Read the rest
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Sometimes configuration needs to be kept in sync between two or more Db2 systems. There are a variety of reasons – sometimes this is for keeping two HADR servers in sync, and other times it may be for keeping a dev, QA, or Staging system in sync with production.… Read the rest
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Db2 needs some temporary space on disk to perform some actions. Commonly we think of these actions as primarily sort and join operations. These are operations where Db2 will first use the SORTHEAP memory area, but some data sets are just too big to fit in these locations.… Read the rest
Continue reading »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.… Read the rest
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Disclaimer: I am not an expert on Oracle RDBMS licensing. Please verify any and all licensing statements about IBM or Oracle before relying on them. I am likely biased towards IBM, having based my career on them, but am not an IBM employee.… Read the rest
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My background comes largely from the physical DBA world, though I’ve gained logical DBA skills over the years. Any reasonably mature IT organization will have a DBA at some level or another review SQL and DDL before it is implemented in production.… Read the rest
Continue reading »Updated 11/22/2017: One-letter typo
If you only ever take the defaults, DB2 places all databases, data, and so forth on one filesystem – whatever filesystem is the home filesystem for the DB2 instance owner. If that is an isolated filesystem, this can be acceptable, but more often it is not, and this is a bad design.… Read the rest
Continue reading »A DB2 DBA must be able to calculate the row width. The row width can be used to estimate table size, and also to pick a tablespace with the correct page size. DB2 is more strict about a row fitting on a page.… Read the rest
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When the client considers high availability and disaster recovery, they often do not know what they are talking about. Many times the client may be dropping buzzwords like “five nines”. To them this is the definition of disaster recovery. In other cases, they are thinking of a worst-case scenario where a whole data center falls off the face of the earth and they need high availability.… Read the rest
I have written quite a few articles on TSA, but thus far, they’ve been strongly focused on the basic how-to. I think this is because so many of us start with the how of a technical topic. As my knowledge has advanced, I have developed more advanced presentations on TSAMP, but I need to also bring that content into the blog.… Read the rest
Continue reading »I have been working with multiple instances on Windows servers lately, and have learned a few things about them, so I thought an article about multiple instances in general would be a good thing.
First, if you don’t understand what an instance is, check out my earlier blog entry: DB2 Basics: What is an Instance?… Read the rest
Continue reading »NOTE: Please do not attempt to architect a high-availability solution without a DB2 expert involved. There are many questions and answers needed beyond those here to make the best decision and ask all the tough questions.
High Availability and Disaster Recovery often have different goals and priorities.… Read the rest
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