I didn't get a chance to investigate thoroughly or get any benchmarks. We were looking for an alternate indexing strategy to B+ trees (with JDBM2) since we knew the keys a priori, but looking at the source I was a bit daunted at porting it and the license wasn't something that we could use.
I started and it bit back enough that I abandoned pursuit. ;) On Tue, Jul 19, 2011 at 6:15 AM, Claudio Martella < [email protected]> wrote: > This looks great. Actually, more than BDZ, the intriguing part is CHM as > it's order preserving. > I guess how it behaves for unseen keys. Do you know about it? > > What did you find more intriguing on this topic? :) > > > On 7/19/11 3:02 AM, Casey Stella wrote: > > I looked into MPH a while ago and came across Sebastiano's work, but was > > even more intrigued by CMPH (http://cmph.sourceforge.net/), > > which claims to work on the order of a billion keys. I attempted a java > > port of BDZ (acyclic random 3-graphs FTW :) at one point, but gave up as > I > > found something > > else a bit more suitable for my needs. > > > > On Mon, Jul 18, 2011 at 12:32 PM, Stack <[email protected]> wrote: > > > >> On Mon, Jul 18, 2011 at 9:22 AM, Claudio Martella > >> <[email protected]> wrote: > >>> Yes, I had a look at it a while ago. For what I know perfect hashing > >>> doesn't work that good for many elements. With millions of items it > >>> should be computationally expensive and the probability of finding such > >>> a perfect hashing. Did you ever test this out? I think I can easily > >>> generate some millions of UUIDs and see how it goes. > >> I never tried it. I was just citing the technique. Even if it > >> worked, Sebastiano's work is all LGPL so we would not be able to use > >> it in our Apache project (unfortunately). > >> > >> St.Ack > >> > > > -- > Claudio Martella > Free Software & Open Technologies > Analyst > > TIS innovation park > Via Siemens 19 | Siemensstr. 19 > 39100 Bolzano | 39100 Bozen > Tel. +39 0471 068 123 > Fax +39 0471 068 129 > [email protected] http://www.tis.bz.it > > Short information regarding use of personal data. According to Section 13 > of Italian Legislative Decree no. 196 of 30 June 2003, we inform you that we > process your personal data in order to fulfil contractual and fiscal > obligations and also to send you information regarding our services and > events. Your personal data are processed with and without electronic means > and by respecting data subjects' rights, fundamental freedoms and dignity, > particularly with regard to confidentiality, personal identity and the right > to personal data protection. At any time and without formalities you can > write an e-mail to [email protected] in order to object the processing of > your personal data for the purpose of sending advertising materials and also > to exercise the right to access personal data and other rights referred to > in Section 7 of Decree 196/2003. The data controller is TIS Techno > Innovation Alto Adige, Siemens Street n. 19, Bolzano. You can find the > complete information on the web site www.tis.bz.it. > > > > >
