The skyline operator is a non-standard extension (even SQL:2008 does
not include it). Queries of that type can be expressed in standard
SQL (although a bit clumsy and the execution is slow). Others have
also worked on extending PostgreSQL with the skyline operator, see:
http://archives.postgresql.org/pgsql-hackers/2007-03/thrd9.php#00188
Nevertheless we find it interesting and did our own implementation of
BNL and SFS. It must be considered as WIP (work in progress). We
highly welcome your feedback.
Through a web frontend it is possible to test-drive the
implementation. Sample queries are given, see:
http://skyline.dbai.tuwien.ac.at/
The source code (patch) is available at:
http://skyline.dbai.tuwien.ac.at/skyline-of-200811131.patch.tar.gz
This patch applies against 8.3.5. In case of interest a patch against
-head can be provided.
References:
[Borzsonyi2001] Börzsönyi, S.; Kossmann, D. & Stocker, K.:
The Skyline Operator, In ICDE, 2001, 421--432
Best,
Hannes