sql

A self drive computer science degree, 2025 edition

What is you want to study computer science, but can’t afford university fees? Or, studied computer science a really long time ago and want to see what’s changed? Or just like learning stuff? Well, lots of schools now post their lectures on YouTube, so its entirely possible to construct a zero cost “self driving degree”, as long as you’re good enough at Canva to make your own certificate at the end. I consider this list incomplete, but in the end I decided I’d post the things from 2025 that I’d found and liked. I can always do an updated version later.

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I really wanted to like etcd, but Andy Pavlo was right

Andy Pavlo of the CMU Database Group is well known for saying that while NoSQL databases acquire cyclical popularity, all databases eventually iterate back to a SQL interface — it happened with MongoDB and Google’s BigTable for example.

I think I have hit that point with etcd. Initially I ported from MySQL to etcd because I really wanted the inexpensive distributed locking and being able to watch values. However, I never actually watch values in my code any more, and I now spend a huge amount of my time maintaining what my code calls “caches”, but which I can now see are just poorly implemented secondary indexes. The straw that broke the camel’s back was https://github.com/etcd-io/etcd/issues/9043, which changed etcd’s defaults to only being able to return 1.5mb in a RPC request.

I therefore think it might be time for me to port back to a real SQL database, perhaps keeping etcd to manage distributed locks. Perhaps.

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Juno nova mid-cycle meetup summary: DB2 support

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This post is one part of a series discussing the OpenStack Nova Juno mid-cycle meetup. It's a bit shorter than most of the others, because the next thing on my list to talk about is DB2, and that's relatively contained. IBM is interested in adding DB2 support as a SQL database for Nova. Theoretically, this is a relatively simple thing to do because we use SQLAlchemy to abstract away the specifics of the SQL engine. However, in reality, the abstraction is leaky. The obvious example in this case is that DB2 has different rules for foreign keys than other SQL engines we've used. So, in order to be able to make this change, we need to tighten up our schema for the database. The change that was discussed is the requirement that the UUID column on the instances table be not null. This seems like a relatively obvious thing to allow, given that UUID is the official way to identify an instance, and has been for a really long time. However, there are a few things which make this complicated: we need to understand the state of databases that might have been through a long chain of upgrades from previous…

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MySQL Tech Talks

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Three intrepid MySQLers came to Google after the user conference to give internal tech talks. They were kind enough to agree to us hosting them for other people to see. The first two are up, so I'll mention those now, and put a link to the last one when it's available... Click on the thumbnail to be taken to the video. Jay Pipes is a co-author of the recently published Pro MySQL (Apress, 2005), which covers all of the newest MySQL 5 features, as well as in-depth discussion and analysis of the MySQL server architecture, storage engines, transaction processing, benchmarking, and advanced SQL scenarios. You can also see his name on articles appearing in Linux Magazine and can read more articles about MySQL at his website. Jay Pipes is MySQL's Community Relations Manager for North America. Learn where to best focus your attention when tuning the performance of your applications and database servers, and how to effectively find the "low hanging fruit" on the tree of bottlenecks. It's not rocket science, but with a bit of acquired skill and experience, and of course good habits, you too can do this magic! Timour Katchaounov The first part of this talk describes…

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