Head First SQL, 2nd Edition

Chapter 14. Transactions and Locks Concurrency Concepts

A Note for Early Release Readers

With Early Release ebooks, you get books in their earliest form—the author’s raw and unedited content as they write—so you can take advantage of these technologies long before the official release of these titles.

This will be the 14th chapter of the final book. Please note that the GitHub repo will be made active later on.

If you have comments about how we might improve the content and/or examples in this book, or if you notice missing material within this chapter, please reach out to the editor at [e-mail].

Juggling a lot of things at once? If it seems like you’re constantly spinning plates, just imagine how your RDBMS feels. When multiple users toss and catch in the same database, they’ll eventually attempt to access and update the same data at the same time. Your system needs the chops to deal with these concurrent events, which is where transactions and locks come in. Transactions help you execute several queries as one unit, while locks allow you to block others from interfering with the data you’re working on. Think you can keep all the balls in the air? Well, practice makes perfect.

Funding your next travels

Now that Abby has a team of data professionals on her side, she’s ready to jet off on her next adventure. But first, she needs to fund her trip.

Abby checks ...