I'm not sure of the less than vs less than or equals in this one, so it may be
my ignorance... but which partition gets records with a date of '24-02-01", it
seems that without a more explicit definition there is ambiguity on dates at
the partition limits when those dates are common to multiple partitions?
To avoid this shouldn't the definition be:
> xof=# create table t (pk bigint not null, ts timestamp not null) partition by
> range (ts, pk);
> CREATE TABLE
> xof=# create table t1 partition of t for values from
> ('2024-01-01'::timestamp, minvalue) to ('2024-01-31'::timestamp, maxvalue);
> CREATE TABLE
> xof=# create table t2 partition of t for values from
> ('2024-02-01'::timestamp, minvalue) to ('2024-02-29'::timestamp, maxvalue);
Brent Wood
Principal Technician, Fisheries
NIWA
DDI: +64 (4) 3860529
________________________________
From: Christophe Pettus <[email protected]>
Sent: Wednesday, September 11, 2024 10:13
To: pgsql-general <[email protected]>
Subject: Overlapping values (?) in multi-column partitioned tables
Hi,
I am clearly not understanding something. Consider:
> xof=# create table t (pk bigint not null, ts timestamp not null) partition by
> range (ts, pk);
> CREATE TABLE
> xof=# create table t1 partition of t for values from
> ('2024-01-01'::timestamp, minvalue) to ('2024-02-01'::timestamp, maxvalue);
> CREATE TABLE
> xof=# create table t2 partition of t for values from
> ('2024-02-01'::timestamp, minvalue) to ('2024-03-01'::timestamp, maxvalue);
> ERROR: partition "t2" would overlap partition "t1"
> LINE 1: ...on of t for values from ('2024-02-01'::timestamp, minvalue) ...
> ^
> xof=#
In what way do those partitions overlap? In other words, there does not appear
to be a value of (ts, pk) having '2024-01-01'::timestamp <= ts <
'2024-03-01'::timestamp for any pk where it would be ambiguous which partition
that row would go into. (I'm imagining it on a cartesian plane, and there
isn't any overlap between the rectangles those partition boundaries define.)
I'm obviously missing something, but... what? Thank you!
[https://www.niwa.co.nz/static/niwa-2018-horizontal-180.png]
<https://www.niwa.co.nz>
Brent Wood
Principal Technician - GIS and Spatial Data Management
Programme Leader - Environmental Information Delivery
+64-4-386-0529
National Institute of Water & Atmospheric Research Ltd (NIWA)
301 Evans Bay Parade Hataitai Wellington New Zealand
Connect with NIWA: niwa.co.nz<https://www.niwa.co.nz>
Facebook<https://www.facebook.com/nzniwa>
LinkedIn<https://www.linkedin.com/company/niwa>
Twitter<https://twitter.com/niwa_nz>
Instagram<https://www.instagram.com/niwa_science>
YouTube<https://www.youtube.com/channel/UCJ-j3MLMg1H59Ak2UaNLL3A>
To ensure compliance with legal requirements and to maintain cyber security
standards, NIWA's IT systems are subject to ongoing monitoring, activity
logging and auditing. This monitoring and auditing service may be provided by
third parties. Such third parties can access information transmitted to,
processed by and stored on NIWA's IT systems.
Note: This email is intended solely for the use of the addressee and may
contain information that is confidential or subject to legal professional
privilege. If you receive this email in error please immediately notify the
sender and delete the email.
