by: Zoltan Toth, IBM and Michael Feng, IBM A database lock is a mechanism utilized by Db2 to govern the access to a database object amongst different transactions. The following is a list of objects that Db2 usually regulates via the usage of locks: - Table - Table partition -...
Lessons Learned of Locking and Latches Locking and latching are both key mechanisms employed by relational database management systems to ensure data integrity, consistency, and the proper serialization of resources. In the Db2 for z/OS world, IRLM manages the locks, but...
With this month’s topic being “locking, concurrency and waits”, it may not be a bad time to review some of the locking basics. It might help your junior colleagues or your developers to get a better understanding. Hopefully after this article you won’t have to explain any more that “yes a reader...
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Steve Thomas of CA Technologies presents a great introduction into the world of locks, latches, claims and drains. A must see for all developers working wit Db2 for z/OS as well as all DBAs wanting to refresh their knowledge. This session will provide an introduction to how data integrity is...
Some time ago I had a discussion with a DBA who guided the developers to use a singleton SELECT instead of fetching from a cursor in cases where just a single row would be selected. Singleton SELECT is a select statement that returns a single row at most. Even though I did not know any further...
We live in a massively multithreaded world. Lots of actions are occurring around us. We are jumping from one task to another. Every now and then, we have to slow down and stop what we are doing to let another task make its way in the stream of activities. That task isn’t necessarily ours. In...
While Locking and other means of concurrency control are essential to any database management system, they are often the cause of problems in today's production systems. Applications are not always designed with concurrency in mind, so it is not uncommon that with increased transactions volumes...
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