This has been saved for the 8.4 release: http://momjian.postgresql.org/cgi-bin/pgpatches_hold --------------------------------------------------------------------------- Sushant Sinha wrote: > I wrote a headline generation function for my app and I have attached > the patch (against the cvs head). It generates multiple contexts in > which the query appears. Essentially, it uses the cover function to > generate all covers, chooses smallest covers and stretches each > selected cover according to the chosen parameters. I think ideally > changes should be made to prsd_headline function but I couldn't > understand that segment of code well. > > The sql interface is > > headline_with_fragments(text parser, tsvector docvector, text doc, > tsquery queryin, int4 maxcoverSize, int4 mincoverSize, int4 maxWords) > RETURNS text > > This will generate headline that contain maxWords and each cover > stretched to maxcoverSize. It will not add any fragment with less than > mincoverSize. > I am running my app with maxcoverSize = 20, mincoverSize = 5, maxWords = 40. > So it shows roughly two fragments per query. > > If Teoder or Oleg want to add this to main branch, I will be happy to > clean it up and test it better. > > -Sushant. > > > > > On Oct 31, 2007 6:26 PM, Catalin Marinas <catalin.marinas@xxxxxxxxx> wrote: > > On 30/10/2007, Oleg Bartunov <oleg@xxxxxxxxxx> wrote: > > > ok, then you have to formalize many things - how long should be excerpts, > > > how much excerpts to show, etc. In tsearch2 we have get_covers() function, > > > which produces all excerpts like: > > > > > > =# select get_covers(to_tsvector('1 2 3 4 5 3 4 abc x y z 2 3'), '2&3'::tsquery); > > > get_covers > > > ------------------------------------------------ > > > 1 {1 2 3 }1 4 5 {2 3 4 abc x y z {3 2 }2 3 }3 > > > (1 row) > > > > This function generates the lexemes, so cannot be used directly, but > > it is probably a good starting point. > > > > > Once you formalize your requirements, you can look on it and adapt to your > > > needs (and share with people). I think it could be nice contrib module. > > > > It seems that Sushant already wants to implement this function. He > > would probably be faster than me :-) (I'm relatively new to db stuff). > > Since I mainly rely on whatever a web hosting company provides, I'll > > probably stick with a Python implementation outside the SQL query. > > > > Thanks for your answers. > > > > -- > > Catalin > > > > ---------------------------(end of broadcast)--------------------------- > > > > TIP 5: don't forget to increase your free space map settings > > [ Attachment, skipping... ] > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend -- Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
