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/
