Db2 Experts on a Data Science Quest
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.
The recovery history file is one of the many files associated with a database, but it is one of the most important.… Read the rest
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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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HADR does an awesome job of replicating all logged operations to 1-3 standby databases. It is remarkably simple to use and pretty resilient. More than once I’ve started talking to a client about PureScale only to discover their actual high availability and/or disaster recovery needs can easily be met by a 4-server HADR implementation.… Read the rest
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While I have tuned backup performance before, it has often been through physical database changes (spreading tables across more table spaces) that I achieve my greatest results. This post is not about backup performance tuning, but about solving a specific backup duration mystery.… Read the rest
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I’d like to think that I’m pretty decent at backup and recovery. I’ve done hundreds of restores in my career in a vast array of scenarios for real-world recovery, data movement, and fixing developers’ mistakes. Today I saw an error I’ve never seen before, so I thought I’d share.… Read the rest
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Mike guest blogged for me about three and four server HADR clusters before, but I want to blog about it from the perspective of adding a third server into an existing two-server cluster. Please go visit Mike’s article for a more general view of multi-standby HADR.… Read the rest
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There are an astonishing number of vendor solutions available with specific interfaces for DB2. Working with a variety of clients, I see and help to evaluate and implement a variety of backup solutions. I thought I’d share some of the things I look for and work on as part of an implementation.… 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 worked with three different vendors for backup solutions for various clients in the last few months, and several others over the course of my career. When either making archive log decisions or evaluating vendors, it is important to know the DB2 details behind what is going on
I’ve recently implemented native encryption for a small database on a server that is somewhat oversized on CPU and memory. One of the things I noticed after encrypting my database was both increased backup duration and increased backup size.
On this particular system, I take compressed DB2 backups to disk, which is later externalized.… Read the rest
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It’s a question I hear frequently – How can I speed up backups? I thought I’d share some details on doing so.
Any backup cannot be faster than it takes to back up the largest tablespace. Parallelism is essentially done on the tablespace level – meaning one thread per tablespace.… Read the rest
Continue reading »Backups are so ingrained into DBAs. They should really be the first and the last thing we think of and ensure we do properly. We do regular backups so we can get data back in case of some failure, be it human, software, or hardware.… Read the rest
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