Aha! "I sorted the DB in three ways and stored uid of records."
If you want fast access to your records, you must access them through record
number, not UID. DmFindRecordByUID does a STUPID, top down search for a
record with the passed in UID (of course, it cannot do anything else), so
each access is O(n).
Thus keep AND maintain, for each sort key, a vector of record indexes.
Also, for quick access of the key index, allocate enough space for the
entire vector and manipulate it as a whole. This approach is, performance
wise, the best you can expect on the PalmOS if you need multiple keys. It
is neither simple nor of low overhead, however.
-bob mckenzie
-----Original Message-----
From: Wocjciech Gody�ski [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, May 30, 2001 7:53 AM
To: Palm Developer Forum
Subject: Re: Searching records
Holger Klawitter wrote:
> > There is only one problem for me yet.
> > I want my DB to be sorted in three ways.
> > I cannot sort on demand (because of amount of records).
> > What is the way to do that?
>
> Palm OS itself does not provide support for that. But you can
> create an index DB yourself (at 1st launch after HotSync
> for example). The optimal way of implementing it strongly depends
> on your data and sorting key sizes, of course.
Yes. I've done this.
But I cannot do a binary search (as I think).
I sorted the DB in three ways and stored uid of records.
But when searching thru records I have to query for each record (it takes
long time).
Q: how does PalmOS stores sort info in database header?
I've been looking thru Reference for long time, but cannot solve it.
Can't I save sortinfo for each sort order and swap it on demand ?
Thanks for Answer
Wojtek
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