[zasdffaa]

Hmm? This doesn't make much sense. MSSQL does these already I think (except the first)

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- Inlining scalar function calls (less impactful now with Sql Server 2019)

write them as table valued funcs and it'll inline them for you (ugly but it works and is easy)

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- Removing joins from a query when we know it won't impact the number of records

That's just tree pruning. It does that

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- Deepening where conditions against derived tables

If I understand you that's predicate pushdown. MSSQL does it well.

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- Killing "branches" of union queries when they can be determined to not matter statically

Not sure what you mean. Can you give an example?

[i_s]

> This doesn't make much sense. MSSQL does these already I think (except the first)

We tested all of these before taking the time to do the rewriting, and no, either they don't, or they way they did it isn't good enough. You can say I'm lying if you want, I'm not going to spend time arguing about it.

[zasdffaa]

You could post some working examples and show them failing.