On 05/01/2017 04:33 PM, David G. Johnston wrote:
> On Mon, May 1, 2017 at 7:26 AM, Andreas Karlsson <andr...@proxel.se
>     I am not sure I like decorators since this means adding an ad hoc
>     query hint directly into the SQL syntax which is something which I
>     requires serious consideration.
> ​Given that we already have
> ​"​
> prevent optimization
> ​"​
> syntax why do we need a decorator on the CTE?

I do not think I follow. Me and some other people here would ideally allow CTEs to be inlined by default. Some people today use CTEs as optimization fences, to for example control join order, and the suggestion here is to add new syntax for CTEs to allow them to selectively be used as optimization fences.

> ​I would shorten that to "WITH MAT" except that I don't think that
> having two way to introduce an optimization fence is worthwhile.

You mean OFFSET 0? I have never been a fan of using it as an optimization fence. I do not think OFFSET 0 conveys clearly enough to the reader that is is an optimization fence.


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