The Prequel to SQL is SEQUEL

At Re:Invent last week, AWS announced DSQL, their new serverless SQL database. As a fan of distributed SQL databases I have been enjoying reading about the various architectural decisions in Marc Brooker’s blog. One thing I thought was fun to see was the first real retread of the Spanner atomic clocks trick since…Spanner? So I thought this would...

It is the job of modern programming languages to be amenable to abstractions. It should be easy for users to take a little bundle of functionality and reuse it, or build something more complex on top of it, or give it to someone else to use. A good programming language gives you a set of primitives and tools to combine them into more complex...

It is the job of modern programming languages to be amenable to abstractions. It should be easy for users to take a little bundle of functionality and reuse it, or build something more complex on top of it, or give it to someone else to use. A good programming language gives you a set of primitives and tools to combine them into more complex...

Follow me on Bluesky! A Log-Structured Merge tree, or LSM, is a popular data structure for storage engines. It’s what is used by RocksDB, which is sort of the poster child LSM. At a high level, the way an LSM works is that new writes get added to a memory-only index called a memtable and a durable file called a write-ahead log, or WAL. The...

Everything you need to know about query planning can be understood from this query: SELECT * FROM xy WHERE y = 3 ORDER BY x Imagine we have two indexes, one ordered on y, and one ordered on x. Then two possible plans suggest themselves: Plan 1: scan the y index, restricting it to the values of y such that y = 3, then sort the result by x. Plan 2:...