[cognomano]

So… caches. The unfortunate reality of high used systems.

[cwillu]

Or indexes, which are after all a structured way of duplicating data for performance, sometimes so much so that they entirely replace the actual table row lookup.

[gunnarmorling]

Yepp, making exactly that same point in the post:

> This is why we have indexes in databases, which, if you squint a little, are just another kind of materialized view, at least in their covering form.

[samdoesnothing]

Yeah that was a lot of words to say caching is needed sometimes.

As always it's an engineering decision full of tradeoffs. You should never duplicate your data, except when you need to...etc etc.