Re: Question related to partitioning with pg_partman

On 3/8/24 00:23, sud wrote:
> 
> Starting a new thread...
> 
> Something interesting and not sure if its expected behaviour as below. 
> We are also confused a bit here.
> 
> In the below example we created two partitioned tables on timestamptz 
> type columns with different time zones and the child partitions are 
> created appropriately with boundaries as one mid night to next mid night 
> of a day and so on. But when we change the time zone and query the  data 
> dictionary views again, it shows the start and end of the partition 
> boundary as not midnights but different times of the day's values.
> 
> So I was wondering if this can cause us any unforeseen issues in the 
> long run while creating the partitions though partman and persisting the 
> data into the tables from the end users then querying those and having 
> queries properly partitioned pruned?
> or
> should we always set the local timezone as UTC always before running or 
> calling the pg_partman/pg_cron process which creates the partitions? 
> Mainly in a database which serves global users sitting across multiple 
> timezones. And same thing while inserting data into the table, we should 
> use UTC timezone conversion function. Can you please confirm.

'2024-03-07 00:00:00+00' and '2024-03-06 19:00:00-05' are the same time 
as is '2024-03-07 00:00:00-05' and '2024-03-07 05:00:00+00'.

Still I would think for sanity sake you would want to stick with UTC.

> 
> And while checking the timezone using the "show timezone" function it 
> shows the local timezone, so is there any way to see postgres DB the 
> server timezone?

show timezone is the currently set server timezone.

select reset_val from pg_settings where name = 'TimeZone';

would show you what the value would be reset to, e.g it's 'default 
value. For more information do:

select * from pg_settings where name = 'TimeZone';

to see where the 'default' is set.


-- 
Adrian Klaver
adrian.klaver@aklaver.com