Thread: Clever way to check overlapping time intervals ?

Clever way to check overlapping time intervals ?

From
Andreas
Date:
Hi,
is there a clever way to check overlapping time intervals ?
An option named n should be taken from date y to y.
The same name is ok for another interval.

e.g. table :  mytab ( d1 date, d2 date, n text, v text )

There should be a constraint to provide no row can have a d1 or d2 
within the interval of another row in case they have the same n.

And no row can have an interval that encloses an existing interval.


Re: Clever way to check overlapping time intervals ?

From
Andreas Kretschmer
Date:
Andreas <maps.on@gmx.net> wrote:

> Hi,
> is there a clever way to check overlapping time intervals ?
> An option named n should be taken from date y to y.
> The same name is ok for another interval.
>
> e.g. table :  mytab ( d1 date, d2 date, n text, v text )
>
> There should be a constraint to provide no row can have a d1 or d2  
> within the interval of another row in case they have the same n.
>
> And no row can have an interval that encloses an existing interval.

You can use the PERIOD data type:
http://temporal.projects.postgresql.org/reference.html

and the new (since 9.0) exclusion constraint:
http://www.depesz.com/index.php/2010/01/03/waiting-for-8-5-exclusion-constraints/
http://www.google.de/search?hl=de&q=postgresql+exclusion+constraint&aq=0L&aqi=g-L1&aql=&oq=postgresql+exclusion+
http://thoughts.j-davis.com/2010/03/09/temporal-postgresql-roadmap/




Andreas
-- 
Really, I'm not out to destroy Microsoft. That will just be a completely
unintentional side effect.                              (Linus Torvalds)
"If I was god, I would recompile penguin with --enable-fly."   (unknown)
Kaufbach, Saxony, Germany, Europe.              N 51.05082°, E 13.56889°


Re: Clever way to check overlapping time intervals ?

From
pasman pasmański
Date:
You can convert dates to cube, they have overlap operator &&






2011/9/16, Andreas Kretschmer <akretschmer@spamfence.net>:
> Andreas <maps.on@gmx.net> wrote:
>
>> Hi,
>> is there a clever way to check overlapping time intervals ?
>> An option named n should be taken from date y to y.
>> The same name is ok for another interval.
>>
>> e.g. table :  mytab ( d1 date, d2 date, n text, v text )
>>
>> There should be a constraint to provide no row can have a d1 or d2
>> within the interval of another row in case they have the same n.
>>
>> And no row can have an interval that encloses an existing interval.
>
> You can use the PERIOD data type:
> http://temporal.projects.postgresql.org/reference.html
>
> and the new (since 9.0) exclusion constraint:
> http://www.depesz.com/index.php/2010/01/03/waiting-for-8-5-exclusion-constraints/
> http://www.google.de/search?hl=de&q=postgresql+exclusion+constraint&aq=0L&aqi=g-L1&aql=&oq=postgresql+exclusion+
> http://thoughts.j-davis.com/2010/03/09/temporal-postgresql-roadmap/
>
>
>
>
> Andreas
> --
> Really, I'm not out to destroy Microsoft. That will just be a completely
> unintentional side effect.                              (Linus Torvalds)
> "If I was god, I would recompile penguin with --enable-fly."   (unknown)
> Kaufbach, Saxony, Germany, Europe.              N 51.05082°, E 13.56889°
>
> --
> Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org)
> To make changes to your subscription:
> http://www.postgresql.org/mailpref/pgsql-sql
>


--
------------
pasman


Re: Clever way to check overlapping time intervals ?

From
Frank Bax
Date:
On 09/15/11 19:40, Andreas wrote:
> Hi,
> is there a clever way to check overlapping time intervals ?
> An option named n should be taken from date y to y.
> The same name is ok for another interval.
>
> e.g. table : mytab ( d1 date, d2 date, n text, v text )
>
> There should be a constraint to provide no row can have a d1 or d2
> within the interval of another row in case they have the same n.
>
> And no row can have an interval that encloses an existing interval.
>


self join with "OVERLAPS" operator:

select t1.*,t2.* from (select * from mytab) as t1    full join (select * from mytab) as t2    where (t1.d1,t1.d2)
overlaps(t2.d1,t2.d2)