Author here. Redis is definitely faster. I was specifically not going for absolute peak performance for either redis or postgres - that would require going down to the wire protocols. The idea was emphasize that there' a "good enough" level of performance. Once you need that sort of speed - sure, there are ways to achieve it.

> The idea was emphasize that there' a "good enough" level of performance. Once you need that sort of speed - sure, there are ways to achieve it.

To this I would add that more often than not the extra cost and complexity of a memory cache does not justify shaving off a few hypothetical milliseconds from a fetch.

On top of that, some nosql offerings from popular cloud providers already have CRUD operations faster than 20ms.