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PostPosted: Wed Nov 02, 2005 4:09 pm
by dlinder
I've been using oracle and access on my PC to design databases. I'm used to setting up many tables in a database to accomplish what I want to do.

I seem to remember reading somewhere that it's better to have one database per app on the Palm.

For a bike log, my instincts are to have a Bike database, a route database, a maintenance database, and a ride database (possibly others). Information in these databases would be different structures.

Is it okay to use multiple databases?
If it's not okay, or not preferred, are PDB's happy with a mix of completely different structures?
Is any way more efficient than any other?

PostPosted: Thu Nov 03, 2005 12:31 pm
by mlambrigger
The problem is the next: the palm is a database and you can just use tables!!

It is not like Oracle or Access.

Marc Lambrigger

PostPosted: Thu Nov 03, 2005 12:36 pm
by FrankG
I don't recall hearing that it's better to have one database per app than not. Most of my applications have several DBs. I think it's important that the databases get created with the same creator ID as the app so that if the user deletes the app the databases will go away too. So maybe you once heard it's best that they have one creator ID.

Multiple databases are handy for creating a data hierarchy. I have a travel expense application that has a database for trip information and a database for expense items per trip (many to one relationship). Another application creates documents and each document is an individual uniquely named database though all with the same ID.


PostPosted: Thu Nov 03, 2005 1:13 pm
by mlambrigger
Frank what you discuss is about multiple table in a database.

To make fine apps, you must use one database per app, but because the palmOS IS a database system and everything is a table in this OS, you can have only one database for all app. In this database, you have develop one table for trip and another one for expenses.

Did you see what I mean?

Marc Lambrigger

PostPosted: Thu Nov 03, 2005 4:31 pm
by Vilmos
Well each palmOS dbf (database file) is treated as a table -- sort of. It has rows anyway, and you can put ANYTHING in any of the rows. So it doesn't function exactly like a database table either.

It doesn't matter how many dbf's you use, but do be aware that the number or rows you have does matter. For example if you have a table with 20,000 rows of 16 bytes of data each, and another table with 10,000 rows of 32 bytes each, the table with less rows will hotsync significantly faster.