DIM saves time on read and write... Direct reference to an attribute as a discrete variable is where the time-savings is realized.
... david ... David L. Wasylenko President, Pick Professionals, Inc w) 314 558 1482 d...@pickpro.com -----Original Message----- From: u2-users-boun...@listserver.u2ug.org [mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of Wjhonson Sent: Friday, July 27, 2012 12:29 PM To: u2-users@listserver.u2ug.org Subject: Re: [U2] Array Types I would suggest that random writing would have a substantial impact. Reading doesn't have to move the string around, I suggest that's where your real savings comes in. -----Original Message----- From: Brian Leach <br...@brianleach.co.uk> To: 'U2 Users List' <u2-users@listserver.u2ug.org> Sent: Fri, Jul 27, 2012 10:25 am Subject: Re: [U2] Array Types Here's a quick proggy I've scrudged together to get a rough indication - results on my system are: Dynamic Dimensioned Read/random access 18.4 14.2 Read only 3.9 4.6 This is with small records: obviously with larger ones the gaps should widen. Brian PROGRAM testdim DIM SALESREC(10) Open 'BOOK_SALES' To F.SALES Else STOP * Ignore the first run as it loads the file into memory Crt "First dummy run" Fin = @False Select F.SALES Loop ReadNext Id Else Fin = @True Until Fin Do Read SalesRec From F.SALES, Id Else Null Repeat * Now the real one, read and randomly access fields Crt "Dynamic Array" Now = Time() For I = 1 To 100 Fin = @False Select F.SALES Loop ReadNext Id Else Fin = @True Until Fin Do Read SalesRec From F.SALES, Id Else SalesRec = '' End For J = 1 To 100 Attr = Rnd(9) + 1 Temp = SalesRec<Attr> Next Repeat Next Crt "Time taken : ": (Time() - Now) Crt "Dimensioned Array" Now = Time() For I = 1 To 100 Fin = @False Select F.SALES Loop ReadNext Id Else Fin = @True Until Fin Do MatRead SALESREC From F.SALES, Id Else Mat SALESREC = '' End For J = 1 To 100 Attr = Rnd(9) + 1 Temp = SALESREC(Attr) Next Repeat Next Crt "Time taken : ": (Time() - Now) * Now just read overheads no access to fields Crt "Dynamic Array Read Only" Now = Time() For I = 1 To 100 Fin = @False Select F.SALES Loop ReadNext Id Else Fin = @True Until Fin Do Read SalesRec From F.SALES, Id Else SalesRec = '' End Repeat Next Crt "Time taken : ": (Time() - Now) Crt "Dimensioned Array Read Only" Now = Time() For I = 1 To 100 Fin = @False Select F.SALES Loop ReadNext Id Else Fin = @True Until Fin Do MatRead SALESREC From F.SALES, Id Else Mat SALESREC = '' End Repeat Next Crt "Time taken : ": (Time() - Now) STOP -----Original Message----- From: u2-users-boun...@listserver.u2ug.org [mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of jbut...@hampshire.edu Sent: 27 July 2012 16:24 To: U2 Users List Cc: U2 Users List Subject: Re: [U2] Array Types I understand the performance trade off between dynamic and dimensioned arrays but I'm curious about quantifying. I know the answer will depend on hardware and load, but in general at what point (length) do dimensioned arrays become better performing than dynamic? 1000? 10000? 100000? Any examples or benchmarks appreciated. Jeff Butera Sent from my iPhone On Jul 27, 2012, at 11:14 AM, "David L. Wasylenko" <d...@pickpro.com> wrote: > Speed > There is a *long* thread here demonstrating the difference between > *DAYS* of processing and seconds, using large records for demonstration. > > ... david ... > > David L. Wasylenko > President, Pick Professionals, Inc > w) 314 558 1482 > d...@pickpro.com > > > -----Original Message----- > From: u2-users-boun...@listserver.u2ug.org [mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of Bill Brutzman > Sent: Friday, July 27, 2012 10:16 AM > To: U2 Users List > Subject: [U2] Array Types > > I am surprised that anyone uses dimensioned arrays. I use dynamic > arrays for everything. > > If there are any advantages that dimension arrays have over dynamic... please let me know... without getting sentimental. > > --Bill > _______________________________________________ > U2-Users mailing list > U2-Users@listserver.u2ug.org > http://listserver.u2ug.org/mailman/listinfo/u2-users > _______________________________________________ > U2-Users mailing list > U2-Users@listserver.u2ug.org > http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list U2-Users@listserver.u2ug.org http://listserver.u2ug.org/mailman/listinfo/u2-users
