Judy definitely rates a WOW!! > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:pgsql-hackers- > [EMAIL PROTECTED] On Behalf Of Gregory Maxwell > Sent: Friday, September 30, 2005 7:07 PM > To: Ron Peacetree > Cc: Jeffrey W. Baker; pgsql-hackers@postgresql.org; pgsql- > [EMAIL PROTECTED] > Subject: Re: [HACKERS] [PERFORM] A Better External Sort? > > On 9/28/05, Ron Peacetree <[EMAIL PROTECTED]> wrote: > > 2= We use my method to sort two different tables. We now have these > > very efficient representations of a specific ordering on these tables. > A > > join operation can now be done using these Btrees rather than the > > original data tables that involves less overhead than many current > > methods. > > If we want to make joins very fast we should implement them using RD > trees. For the example cases where a join against a very large table > will produce a much smaller output, a RD tree will provide pretty much > the optimal behavior at a very low memory cost. > > On the subject of high speed tree code for in-core applications, you > should check out http://judy.sourceforge.net/ . The performance > (insert, remove, lookup, AND storage) is really quite impressive. > Producing cache friendly code is harder than one might expect, and it > appears the judy library has already done a lot of the hard work. > Though it is *L*GPLed, so perhaps that might scare some here away from > it. :) and good luck directly doing joins with a LC-TRIE. ;) > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend
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