O Oleg Bartunov έγραψε στις Nov 17, 2004 :
> Gary, > > if you need really fast solution for you task and dont't afraid > non-standard soltion, take a look on contrib/ltree module. > http://www.sai.msu.su/~megera/postgres/gist/ltree/ > > Oleg Oleg how would you compare an ltree solution against a genealogical approach using intarray?? i.e. store for each node, its path to root, e.g. path='{4,2,7}'::int4[] where 4 is the id of the father, 2 of the grandfather, and 7 of the root, whereas root has path is null. That way we can do really fast queries using ~, have indexes on level (path length),first (immediate ancestor),last (root) using C functions that we can easily write and so forth. I have extensively used this approach with success. Can you comment on the pros and cons of each? (int[] with intarray vs ltree). Thanx > _____________________________________________________________ > Oleg Bartunov, sci.researcher, hostmaster of AstroNet, > Sternberg Astronomical Institute, Moscow University (Russia) > Internet: [EMAIL PROTECTED], http://www.sai.msu.su/~megera/ > phone: +007(095)939-16-83, +007(095)939-23-83 > > ---------------------------(end of broadcast)--------------------------- > TIP 9: the planner will ignore your desire to choose an index scan if your > joining column's datatypes do not match > -- -Achilleus ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
