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
