RE: [U2] [UV] FIND vs LOCATE- speed?
Thanks for all the replies. I decided to test it. On my system (admittedly without exhaustive testing) I found that FIND and LOCATE have very similar performance with FIND being slightly faster than LOCATE and INDEX being slightly faster than FIND. This was against a 75,000 element dynamic array. Your results may vary. Barry Brevik --- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/
Re: [U2] [UV] FIND vs LOCATE- speed?
Never checked but FIND and LOCATE could be the same subroutine. Lookup in a sorted string is definitely faster - with randomly distributed search strings the expected number of comparisons are halfed. If the strings to lookup tend to be early in the sort order the performance is even better. But You need a good number of searches to pay for the time used to sort. -- mats Barry Brevik wrote: When using FIND or LOCATE on a dynamic array, is one faster than the other, and is there any reason to sort the array to (hopefully) improve the speed of FIND or LOCATE? I don't need to use LOCATE... BY... SETTING, I'm just doing a raw FIND or LOCATE. Barry Brevik --- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/ --- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/
Re: [U2] [UV] FIND vs LOCATE- speed?
I don't know how they're implemented now, but when FIND was first written at Microdata, it was completely separate so it didn't have to deal with much of the LOCATE overhead. They should be about the same speed if the array is unsorted as they both have to scan from start to finish and both will stop at the first match. However, if the array is sorted and you specify ascending or descending in the LOCATE statement, it will stop when a match is NOT found before (usually) the end of the array. So a failure case will usually run faster. If a match ISN'T found, the LOCATE sorted will still be no faster than FIND because both must still search the entire array. Hope this helps. Stewart When using FIND or LOCATE on a dynamic array, is one faster than the other, and is there any reason to sort the array to (hopefully) improve the speed of FIND or LOCATE? I don't need to use LOCATE... BY... SETTING, I'm just doing a raw FIND or LOCATE. Barry Brevik --- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/
RE: [U2] [UV] FIND vs LOCATE- speed?
If you don't care about the resulting position - i.e. you just want to know if the list contains the item, then the absolute quickest method is to use INDEX(). Eg looking for JKL in ABC}DEF}GHI}JKL}MNO}PQR THE.LIST = @VM:ABC}DEF}GHI}JKL}MNO}PQR:@VM IF INDEX(THE.LIST,@VM:JKL:@VM,1) THEN found The extra value marks at the beginning and end are required to ensure the value you're looking for isn't contained within another value. Even if you do need the position, INDEX can be quicker, just use COUNT afterwards to determine the number of marks that appear before the INDEX position. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Barry Brevik Sent: Thursday, 3 August 2006 8:24 AM To: U2-users (E-mail) Subject: [U2] [UV] FIND vs LOCATE- speed? When using FIND or LOCATE on a dynamic array, is one faster than the other, and is there any reason to sort the array to (hopefully) improve the speed of FIND or LOCATE? I don't need to use LOCATE... BY... SETTING, I'm just doing a raw FIND or LOCATE. Barry Brevik --- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/ DISCLAIMER: Disclaimer. This e-mail is private and confidential. If you are not the intended recipient, please advise us by return e-mail immediately, and delete the e-mail and any attachments without using or disclosing the contents in any way. The views expressed in this e-mail are those of the author, and do not represent those of this company unless this is clearly indicated. You should scan this e-mail and any attachments for viruses. This company accepts no liability for any direct or indirect damage or loss resulting from the use of any attachments to this e-mail. --- u2-users mailing list u2-users@listserver.u2ug.org To unsubscribe please visit http://listserver.u2ug.org/
