On 23.11.21 07:18, Maciek Sakrejda wrote:
> An example in the materialized view documentation [1] includes an ORDER
> BY clause without a clear reason. Does it help build the index more
> efficiently? I suppose it's also sort of like a CLUSTER?
>
> But it seems like the ORDER BY should either be explained or dropped: as
> is, this gives the impression that the ORDER BY can be "embedded" into
> the resulting relation and persist to other queries that do not include
> an explicit ORDER BY. (I recently ran across this belief, though not
> sure if this was due to this example.)
>
> Thoughts?
>
> [1]:
> https://www.postgresql.org/docs/current/rules-materializedviews.html
> <https://www.postgresql.org/docs/current/rules-materializedviews.html>
I agree the ORDER BY is not relevant to the example. There might be
some implementation-dependent advantage to ordering a materialized view,
but if there is, it isn't explained in the example.