I think your missing the point of what a list is in ColdFusion in relationship to what an array or structure is. A list is simply a string that will have to be parsed by CF to be seen as a collection of data. After its been parsed it can then be searched. That parsing, especially when done in Java is what the true question is. Will a structure, which already has the individual items separated into storage areas operate faster than a string which has to do more work? I'd expect the structure to be faster, but its not. I think that a new array search function might be in order here. Something to look through an array for a value and return its index.
> I'm not sure what you are really trying to accomplish here. It is a well > known fact that the data structure of choice to do a linear search > against is a list. Any linear search is going to be O(N) plus whatever > overhead each operation incurs and a list has the lowest overhead per > operation. You only want to use arrays or maps (structs) when you > require random access to the data. Arrays tend to be a good way of > representing different types of trees, which generally are the best data > structures to search for a value against. For example, balanced trees > can generally offer O(log N) worst case. Finally, maps are generally > meant to be when you are dealing with known keys. If you know the key, a > map is O(1) for retrieving the value, which is always going to be better > than any other data structure. However, if you attempt to search a map > without knowing a key then you are really no better off than searching a > list. > > See http://www.cs.fiu.edu/~weiss/ for more information on algorithms and > data structures. > > Matt Liotta > President & CEO > Montara Software, Inc. > http://www.montarasoftware.com/ > 888-408-0900 x901 > > > -----Original Message----- > > From: Michael Dinowitz [mailto:[EMAIL PROTECTED]] > > Sent: Wednesday, December 04, 2002 12:06 AM > > To: CF-Talk > > Subject: Lists vs. Arrays vs. Structures > > > > I'm rewriting my CFMakeTree tag in order to make it tighter and work > in > > CFMX > > better. One of the assumptions I had was that Lists would be > problematic > > in > > comparison to Arrays or Structs. My first test was to find a value in > one > > of > > these data collections. > > For Lists I used ListFindNoCase. For Arrays, I looped over the array > to > > find the > > value and for Structs I used StructFindValue(). I ran each test in a > 1000 > > iteration loop to see if anything showed up. On the whole, Arrays took > the > > longest, which is to be expected as they had to loop (no native > arrayfind > > function). Structures took less then 10% of the array time to search > and > > lists > > took 1/3 of the struct time. The data set was 0-9a-z written out in > full > > and the > > item searched for was the z. > > So the results are basically that lists are easier to search than > either > > structures or arrays. > > As a side note, I tried using a query of queries and it was much, much > > slower. > > > > The second experiment was to loop over each data collection. In this, > we > > see > > much different results. > > Arrays were fastest. Lists were anywhere from about as fast as an > array to > > twice > > as slow. Structures tended to be on par with lists, but sometimes > slower. > > On the whole, unless you see a need to, I'd stick with using lists in > > CFMX. I > > have heard of people who have seen some major slowdowns due to lists > and > > I'd > > love to hear the specifics. > > > > Michael Dinowitz > > Master of the House of Fusion > > http://www.houseoffusion.com > > > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Archives: http://www.houseoffusion.com/cf_lists/index.cfm?forumid=4 Subscription: http://www.houseoffusion.com/cf_lists/index.cfm?method=subscribe&forumid=4 FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Get the mailserver that powers this list at http://www.coolfusion.com
