----------
>From: Danny Epstein <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED], "'[EMAIL PROTECTED]'"
<[EMAIL PROTECTED]>, "'[EMAIL PROTECTED]'"
<[EMAIL PROTECTED]>
>Subject: Re: Generating unique record IDs
>Date: Wed, Oct 6, 1999, 6:43 PM
>
> At 11:34 AM -0400 10/6/99, Gordon, Douglas wrote:
>><snip>The main characteristic of the database on the Palm is that it is truly
a
>>sort of database, with numerous "links" between records required. I assume
>>that the only practical way to do this is to use the "unique record ID"
>>field to act as a "pointer" to a related record. <snip>
>
> Because your Palm app is a viewer, you can get away with using record
> numbers for your "links". This will make following "links" quite efficient.
> However, this will require your conduit to re-write entire databases
> whenever anything changes, since later records get renumbered when records
> are inserted or deleted.
>
> If you want your conduit to be as efficient as possible, you should use
> your own ID field. Reserve some bytes in each record for a unique ID which
> you generate. You can store the last ID generated in the app info block. If
> possible, sort your databases by this ID. This will allow you to follow a
> "link" without having to scan all the records. (You'll have to work around
> the off-by-one bug in DmFindSortPosition.) Whether all this is worth the
> trouble is questionable in your case since the data changes infrequently.
>
> I'd probably use record numbers.
> -
> Danny Epstein, Applied Thought Corporation
> Have friends with Palm organizers? Get BeamBooks!
> http://www.appliedthought.com/beambooks
>
>
