Preparing to Upsize Your Jet Applications

There are two basic approaches to increasing the probability of a fully successful upsizing operation:

• Trial and error Run the Wizard early and often to determine the scope of the additional effort necessary to upsize your Jet application successfully. If you have very large tables, you can use the structure-only option to minimize upsizing time. Read the Upsizing Wizard's report, make the changes necessary to upgrade missing objects, and try again.

• Planned migration Make changes to the Jet tables, queries, and application objects to minimize the likelihood of upsizing problems. For example, convert your VBA code that uses Data Access Objects (DAO) to ActiveX Data Objects (ADO) that use the OLE DB data provider for Jet. Thoroughly test your changes.

If your Jet application is relatively simple or in the early development stage and doesn't include VBA code that has reference to any version of DAO, the trial-and-error method might be your best choice. The most efficient upsizing method usually is a combination the two approaches.

Tip

Replace all instances of Like expressions for date constraints in Jet query WHERE clauses with Between...And expressions. For example, change Like "*/*/1997" to Between #1/1/1997# And #12/31/1997#. The Wizard upsizes Like "*/*/1997" to LIKE '%/%/1997", but the upsized query returns no rows in the project designer.