[mjb]

Introductory material is always welcome, but I suspect this isn't going to hit the target for most people. For example:

> Therefore, if the price isn’t an issue, SSDs are a better option — especially since modern SSDs are just about as reliable as HDDs

This needs a tiny extra bit of detail: if you're buying random IO (IOPS) or throughput (MB/s), SSDs are significantly (orders of magnitude!) cheaper than HDDs. HDDs are only cheaper on space, and only if your need for throughput or IO doesn't cause you to "strand" space.

> Consistency can be understood after a successful write, update, or delete of a row. Any read request immediately receives the latest value of the row.

This isn't the ACID definition of C, and is closer to the distributed systems (CAP) one. I can't fault the article for getting this wrong, though - it's super confusing!

[googletron]

You are absolutely right about the C being more inline with CAP one.

I have a post in draft to discuss disk trade offs which digs into this aspect, its impossible to dig into everything in this level of a post.