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From: Jim Nasby <[email protected]>
To: PostgreSQL-documentation <[email protected]>
Subject: Inconsistency in docs for OVERLAPS
Date: Tue, 20 Apr 2010 18:34:00 -0500
Message-ID: <[email protected]> (raw)

Per 8.3 and 8.4 docs:

"In addition to these functions, the SQL OVERLAPS operator is supported:

(start1, end1) OVERLAPS (start2, end2)
(start1, length1) OVERLAPS (start2, length2)
This expression yields true when two time periods (defined by their endpoints) overlap, false when they do not overlap. The endpoints can be specified as pairs of dates, times, or time stamps; or as a date, time, or time stamp followed by an interval."

So we accept (datetime,datetime) OVERLAPS (datetime,datetime) or (datetime,interval) OVERLAPS (datetime,interval)

However, the example shows yet another case:

"SELECT (DATE '2001-02-16', DATE '2001-12-21') OVERLAPS

       (DATE '2001-10-30', DATE '2002-10-30');

Result: true

SELECT (DATE '2001-02-16', INTERVAL '100 days') 
OVERLAPS

       (DATE '2001-10-30', DATE '2002-10-30');

Result: false

And in reality, (timestamp, interval) OVERLAPS (timestamp, timestamp) does work, first part of this is incomplete.
--
Jim C. Nasby, Database Architect                   [email protected]
512.569.9461 (cell)                         http://jim.nasby.net

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