1. Splitting a Database: How and Why Roger Smeaton

2. CONTENTS Splitting a database - what is it? Why do it? How is it done?

3. One-file architecture Access database  Tables  Relationships  Forms  Queries  Reports  Macros  Modules (VBA code) Only one database file, has it all!

4. Two-file architecture Front-end (application) – the user interface Back-end – the data

5. Forms Queries Reports Macros Modules (VBA code) Front-end Back-end Tables Relationships

6. Each user gets their own copy One shared copy, on the server Front-end Back-end

7. Why split a database ? 1.Separates data (back-end) from application (front-end). Developer can make changes to the application without disturbing the data or the users.

8. Why split a database ? 2. Able to create temporary tables in the front-end. Stores intermediate results, run- time parameters, etc.

9. Why split a database ? 3. Performance. Each user has a copy of the user interface (in the front-end), so network traffic is reduced.

10. Do I have to split? Not necessary to split if ofront-end is stable (no changes) and osingle user and onetwork overhead is not a problem

11. When to split After you have designed your tables, relationships, forms, etc. but before you release the software to the users.

12. How to split a database OPTION 1 – use the Database Splitter wizard Open the file. From the Tools menu, Database Utilities  Database Splitter and follow the directions. OPTION 2 – do it manually [details omitted]

13. After you split … Compact the front-end file How? From the Tools menu, select Database Utilities  Compact and Repair Database

14. DEMO Access database Northwind.mdb

15. Ready to deploy the database? 1.Copy the back-end to a shared network device. 2.Re-link the tables in the front-end. (Why? To point to the actual data tables in their new location) 3.Copy the front-end to each user’s PC. Not mandatory but strongly recommended

16. Re-linking Once you have linked to the tables in the back-end, you can use the Linked Table Manager to re-link. How? From the Tools menu, select Database Utilities  Linked Table Manager