Actually thinking about this his biggest problem may actually be NT/Win2000 scheduling, and will need to change the priority of the thread/process to real-time/highest priority if/when required, as a scheduling switch will in all cases take much longer than finding the item.
PS: From reading the MS threading docs (somewhere), I read that the scheduler first services all threads at the highest priority, then once none of them require action, then moves to the next lower priority and so on. SO it can take a while to get to a normal application level thread. Myles. -----Original Message----- From: Neven MacEwan [mailto:[EMAIL PROTECTED]] Sent: Friday, 2 November 2001 10:03 a.m. To: Multiple recipients of list delphi Subject: Re: [DUG]: Dynamic Arrays V Strings Lists Chris I don't think you read the original post correctly David was requiring a 'microseconds' response, pretty much rules out any disk access Neven ----- Original Message ----- From: "Chris Reynolds" <[EMAIL PROTECTED]> To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]> Sent: Friday, November 02, 2001 8:33 AM Subject: RE: [DUG]: Dynamic Arrays V Strings Lists > Maybe. > A 'file of record' with an in-memory hash or nary-tree index will get you > there in one disk access and not significantly more than 19 key comparisons. > This may be a lot better than an enormous in-memory structure and the > vagarities of the virtual memory system (unless of course, you pin it in > memory) > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On > Behalf Of Neven MacEwan > Sent: Thursday, November 01, 2001 11:00 PM > To: Multiple recipients of list delphi > Subject: Re: [DUG]: Dynamic Arrays V Strings Lists > > > David > > Can you give more info > > 1/ How are you accessing the info, by position or indexed (and how many > ways, and by what type of keys, string, integer etc) > > 2/ Is the data static or dynamic (ie can you stream the data in and then > sort it or is it constantly updated) > > 5/ Are the records fixed length > > 4/ What sort lookup time are you aiming at? > > My gut feeling is (assuming 1 index, fixed length data) > > 1/ Allocate a f***ing great array of records > 2/ Stream in your data using a hash function to position them in your array > 3/ Lookup using a hash then linear search > > You are going to require a Gig of memory anyway > > HTH > > Neven > > ----- Original Message ----- > From: "David Smith" <[EMAIL PROTECTED]> > To: "Multiple recipients of list delphi" <[EMAIL PROTECTED]> > Sent: Thursday, November 01, 2001 5:00 PM > Subject: [DUG]: Dynamic Arrays V Strings Lists > > > > Hi, > > > > Any one have ideas or experience if Dynamic arrays or string\object lists > is > > faster for accessing an element. > > > > Am developing an application where microns (maybe microseconds) for > > accessing an item in a list over 500 000 items (about 1500 bytes each) > based > > on an index is very important. > > > > Thanks, > > David. > > > > > -------------------------------------------------------------------------- - > New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] > Website: http://www.delphi.org.nz > To UnSub, send email to: [EMAIL PROTECTED] > with body of "unsubscribe delphi" > Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ > > -------------------------------------------------------------------------- - > New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] > Website: http://www.delphi.org.nz > To UnSub, send email to: [EMAIL PROTECTED] > with body of "unsubscribe delphi" > Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ > --------------------------------------------------------------------------- New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] Website: http://www.delphi.org.nz To UnSub, send email to: [EMAIL PROTECTED] with body of "unsubscribe delphi" Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/ --------------------------------------------------------------------------- New Zealand Delphi Users group - Delphi List - [EMAIL PROTECTED] Website: http://www.delphi.org.nz To UnSub, send email to: [EMAIL PROTECTED] with body of "unsubscribe delphi" Web Archive at: http://www.mail-archive.com/delphi%40delphi.org.nz/
