Try hash table with double hashing. Something like this http://www.java2s.com/Code/Java/Collections-Data-Structure/Hashtablewithdoublehashing.htm
2011/3/17 Peter Haidinyak <phaidin...@local.com> > Hi, > This is a little off topic but this group seems pretty swift so I > thought I would ask. I am aggregating a day's worth of log data which means > I have a Map of over 24 million elements. What would be a good algorithm to > use for generating Hash Codes for these elements that cut down on > collisions? I application starts out reading in a log (144 logs in all) in > about 20 seconds and by the time I reach the last log it is taking around > 120 seconds. The extra 100 seconds have to do with Hash Table Collisions. > I've played around with different Hashing algorithms and cut the original > time from over 300 seconds to 120 but I know I can do better. > The key I am using for the Map is an alpha-numeric string that is > approximately 16 character long with the last 4 or 5 character being the > most unique. > > Any ideas? > > Thanks > > -Pete >
