Daterange question

On 1/19/24 20:08, Andreas Joseph Krogh wrote:

I have order-lines with start-end like this:

|start_date DATE NOT NULL, end_date DATE, drange daterange NOT NULL
GENERATED ALWAYS AS (daterange(start_date, end_date, '[)')) STORED|

and have an index on |using gist(drange)|

I want to list all order-lines which does not have end-date set in the
past, but want to show lines with start-dates in future.

This seems to do what I want:

|NOT (drange << daterange(CURRENT_DATE, NULL, '[)'))|

But this doesn't use the index.

Any idea how to write a query so it uses the index on |drange|?

Without the full query and the EXPLAIN output I don't see that there is
much that can be offered in way of an answer.

Thanks.

--
*Andreas Joseph Krogh*
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andreas@visena.com <mailto:andreas@visena.com>
www.visena.com <https://www.visena.com&gt;
<https://www.visena.com&gt;

--
Adrian Klaver
adrian.klaver@aklaver.com

create table order_line ( id serial primary key, start_date DATE NOT NULL,
end_date DATE, drange daterange NOT NULL GENERATED ALWAYS AS
(daterange(start_date, end_date, '[)')) STORED ); CREATE INDEX
order_line_not_end_idx ON order_line using gist(drange); INSERT INTO
order_line(start_date, end_date) values('2023-01-01', null); INSERT INTO
order_line(start_date, end_date) values('2023-01-01', '2024-01-01'); INSERT
INTO order_line(start_date, end_date) values('2024-01-01', null); INSERT INTO
order_line(start_date, end_date) values('2025-01-01', null); set enable_seqscan
to false; explain analyse select * from order_line WHERE (drange <<
daterange(CURRENT_DATE, NULL, '[)')); -- Uses index
┌────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ QUERY PLAN │
├────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Index Scan using order_line_not_end_idx on order_line (cost=0.14..8.15 rows=1
width=44) (actual time=0.008..0.008 rows=1 loops=1) │ │ Index Cond: (drange <<
daterange(CURRENT_DATE, NULL::date, '[)'::text)) │ │ Planning Time: 0.043 ms │
│ Execution Time: 0.013 ms │
└────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
explain analyse select * from order_line WHERE NOT (drange <<
daterange(CURRENT_DATE, NULL, '[)')); -- Does not use index
┌─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ QUERY PLAN │
├─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┤
│ Seq Scan on order_line (cost=10000000000.00..10000000001.07 rows=3 width=44)
(actual time=0.007..0.008 rows=3 loops=1) │ │ Filter: (NOT (drange <<
daterange(CURRENT_DATE, NULL::date, '[)'::text))) │ │ Rows Removed by Filter: 1
│ │ Planning Time: 0.077 ms │ │ Execution Time: 0.015 ms │
└─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘

--
Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andreas@visena.com <mailto:andreas@visena.com>
www.visena.com <https://www.visena.com&gt;
<https://www.visena.com&gt;

Adrian Klaver <adrian.klaver@aklaver.com> writes:

On 1/19/24 20:08, Andreas Joseph Krogh wrote:

This seems to do what I want:
|NOT (drange << daterange(CURRENT_DATE, NULL, '[)'))|
But this doesn't use the index.
Any idea how to write a query so it uses the index on |drange|?

Without the full query and the EXPLAIN output I don't see that there is
much that can be offered in way of an answer.

Well, we can definitively state that the NOT makes this unindexable.
You need a WHERE clause that looks like
indexed-column indexable-operator pseudo-constant
which this isn't, nor does << have a negator operator that could
allow the NOT to be simplified out.

Wouldn't
drange && daterange(CURRENT_DATE, NULL, '[)')
serve the purpose? That should be indexable.

regards, tom lane

På lørdag 20. januar 2024 kl. 06:35:07, skrev Tom Lane <tgl@sss.pgh.pa.us
<mailto:tgl@sss.pgh.pa.us>>:
[…]
Well, we can definitively state that the NOT makes this unindexable.
You need a WHERE clause that looks like
indexed-column indexable-operator pseudo-constant
which this isn't, nor does << have a negator operator that could
allow the NOT to be simplified out.

Wouldn't
drange && daterange(CURRENT_DATE, NULL, '[)')
serve the purpose? That should be indexable.

regards, tom lane
Yes it will, thanks.

--
Andreas Joseph Krogh
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andreas@visena.com <mailto:andreas@visena.com>
www.visena.com <https://www.visena.com&gt;
<https://www.visena.com&gt;