Comments on: Temporal PostgreSQL Roadmap

By: Oleg Bartunov

Oleg Bartunov — Wed, 20 Apr 2011 13:27:31 +0000

Fuzzy date, fuzzy interval, Allen’s algebra,…,etc. This is a big and separate topic. I’m thinking about hdate data type for historical data and looks like it should looks like,
{date1,date2, pdate1,pdate2,…,pdateN}, where date1,date2 – are dates to represent fuzzy date and pdates are probable dates, ordered by reliability. Example: in the beginning of 20-th century, but most probable in 1925 or 1927 year. Then, we could store this like: {01-01-1900,31-12-1999, 01-01-1925,31-12-1925,01-01-1927,31-13-1927}. pdates here represents as two dates, since they are fuzzy.

By: Jeff Davis

Jeff Davis — Thu, 11 Mar 2010 04:54:05 +0000

This can be modeled in a way similar to numbers with only a few significant figures: truncation.

For example, you can use a CHECK constraint like “CHECK(the_month = date_trunc(‘month’, the_month))”. This might be a good use for domains.

By: Scott Bailey

Scott Bailey — Thu, 11 Mar 2010 04:46:44 +0000

Richard, You can install chronosDB over top of Jeff's period data type. ChronosDB does things like union, minus and intersect non-contiguous sets (arrays of periods)

By: Richard Broersma Jr.

Richard Broersma Jr. — Wed, 10 Mar 2010 23:02:25 +0000

Yes, either overlapping or touching (is overlapping the same a touching?). Having this would make be a really nice feature that (to me) would simply range queries.

By: David Fetter

David Fetter — Wed, 10 Mar 2010 20:59:40 +0000

By “continuous ranges,” do you mean something that knows that “melts” two or more overlapping, non-identical intervals into their union? That sounds really neat!

By: Joe

Joe — Wed, 10 Mar 2010 17:29:17 +0000

Not sure if this falls into TEMPORAL data types, but I’ve found a need for what I call a FUZZY DATE. For example, a blog post may have a precise date, like 2010/03/09, and you may know the precise date of a person’s birth or some other event. However, some events or dates are less precise, e.g., a monthly magazine may have a publication date of March 2010, a quarterly journal may be dated Winter 2010, a book may have simply have a year as copyright date, and sometimes you may only know a historical date only approximately, e.g., circa 1502. You’d still like to order the events/date in some reasonable manner or search for events that took place in March 2010 and find the journal, the magazine and the blog post.

By: Richard Broersma Jr.

Richard Broersma Jr. — Wed, 10 Mar 2010 12:41:04 +0000

One lesser feature that I believe may be useful would be range aggregates. Rather than simply summing the durations of a range for a group, it would be nice to get a set of continuous ranges for the group.

By: akretschmer

akretschmer — Wed, 10 Mar 2010 06:20:48 +0000

I have seen a very interesting presentation from Magnus Hagander (at FOSDEM 2010 Brussels) about this great feature – and i hope, 9.1 will contains this great feature.

I wish you success!

Regards, Andreas