Обсуждение: Using SKYLINE command on PostgreSQL
Hello, I have just installed version 8.4 of PostGresql (on a Windows machine) in order to use SKYLINE command, but it seems that I get an error each time I try to use this command. Is there a specific plugin to install to add SKYLINE command ? Can you help me on this point to get this command working ? Thank you.
On 05/08/10 00:26, LaboRecherche wrote: > > > Hello, > > I have just installed version 8.4 of PostGresql (on a Windows machine) > in order to use SKYLINE command, but it seems that I get an error each > time I try to use this command. > > Is there a specific plugin to install to add SKYLINE command ? Can you > help me on this point to get this command working ? All I can find with a quick Google search for "SKYLINE postgresql" is references to someone's masters thesis, plus a bit of mailing list discussion. There's no indication it was ever proposed and discussed as a serious patch to the core of PostgreSQL, let alone applied. Have a look at this thead, including follow-ups. http://archives.postgresql.org/pgsql-hackers/2007-03/msg00192.php The masters thesis page does contain a patch against PostgreSQL 8.3: http://skyline.dbai.tuwien.ac.at/ but this is something you have to apply to the source code, then compile PostgreSQL into usable binaries. That's trivial on Linux, but I don't recommend you try it on Windows, as compiling software on Windows is much more complex. They say they're porting the patch to 8.4devel, but I suspect that since 8.4 has been out for ages and 9.0 is almost released, they've probably lost interest and dropped the work. -- Craig Ringer
On Sun, Aug 8, 2010 at 5:35 AM, Craig Ringer <craig@postnewspapers.com.au> wrote:
That page has a nice web page and examples where queries can be run. 'The skyline operator' is described in http://www.dbis.ethz.ch/research/publications/38.pdf. It reminds me a bit of the staircase join operator, something on my personal wish list for postgres as well (latest patch seems to have got lost on the internet).
I looked a bit in the latest patch. There's a lot of FIXME's and TODO's in it. It adds at least one plan node, so it's probably hard to rewrite into contrib form. That'll probably make it harder to get accepted for mainline postgres, also because the skyline queries can be translated into 'normal' sql (referenced pdf, section 3.1), though the authors claim the performance using skyline is better. Since 8.3 CTE's have been introduced and maybe that makes writing these kinds of queries easier. Also the knngist ordering of 'interesting points' might be a solution for problems in the same ballpark.
regards,
Yeb Havinga
The masters thesis page does contain a patch against PostgreSQL 8.3:
http://skyline.dbai.tuwien.ac.at/
That page has a nice web page and examples where queries can be run. 'The skyline operator' is described in http://www.dbis.ethz.ch/research/publications/38.pdf. It reminds me a bit of the staircase join operator, something on my personal wish list for postgres as well (latest patch seems to have got lost on the internet).
They say they're porting the patch to 8.4devel, but I suspect that since
8.4 has been out for ages and 9.0 is almost released, they've probably
lost interest and dropped the work.
I looked a bit in the latest patch. There's a lot of FIXME's and TODO's in it. It adds at least one plan node, so it's probably hard to rewrite into contrib form. That'll probably make it harder to get accepted for mainline postgres, also because the skyline queries can be translated into 'normal' sql (referenced pdf, section 3.1), though the authors claim the performance using skyline is better. Since 8.3 CTE's have been introduced and maybe that makes writing these kinds of queries easier. Also the knngist ordering of 'interesting points' might be a solution for problems in the same ballpark.
regards,
Yeb Havinga