>-----Oprindelig meddelelse-----
>Fra: Francisco Olarte <fola...@peoplecall.com>
>Sendt: 10. april 2021 09:31
>Til: Niels Jespersen <n...@dst.dk>
>
>Although it is equivalent I would suggest to use:
>
>f.r_time< ('2020-10-01 00:00:00+00'::timestamptz at time zone 'utc' + interval
>'1 month') at time zone 'utc' ;
>
>optimizer should treat both the same, but I'm no sure it can recognize it, and
>it may not see your condition is of the type "field < constant" to select
>index scans and similar things. Also, you can refactor your calculations into
>an stable function for greater clarity.
The plannes seems to be able to figure this out nicely.
>
>> I think maybe it's better to just change the session timezone when this need
>> arises.
>
>Maybe. Also, I do not see the need to query exact partitions by tstz range,
>but assuming you do it may be much easier to query the catalog for the
>partition and then query the partition. ( In many years of working with
>time-partitioned tables I have never got the need to build a query to hit
>exactly X partitions from times ).
>
I need to hit an exact partition, because the query makes some QA on data
coming from a file that fits that exact timeslot. File and partition must match
exactly because the file may be raplaced later and the partition truncated.
Thank you for your insights.
Niels
>Francisco Olarte.
