Re: ORDER BY in materialized view example? - Mailing list pgsql-docs

From Peter Eisentraut
Subject Re: ORDER BY in materialized view example?
Date
Msg-id 1e9f99f9-9cdb-4bc3-85d9-c017fbc54566@enterprisedb.com
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In response to ORDER BY in materialized view example?  (Maciek Sakrejda <m.sakrejda@gmail.com>)
Responses Re: ORDER BY in materialized view example?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-docs
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.



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