Microsoft Access 2010 Bible

Part IV: Professional Database Development

854

End If

Next ref

ExitHere:

Exit Function

HandleError:

MsgBox Err & “: “ & Err.Description

ReferenceFromFile = False

Resume ExitHere

End Function

With the References collection, the primary concern of using and distributing libraries — losing

references upon distribution — is now gone. However, library databases still have one major draw-

back: Access libraries don’t support circular references. This means that the code in your library

databases can’t reference variables or call procedures that exist in your parent database.

Whether you distribute your application as one database or as a primary database that uses library

databases, if your applications are static (they don’t allow modification of objects by end users or

wizards and don’t perform object modifications on themselves), you should always distribute the

databases in a fully compiled state so that your users experience the highest level of performance.

Improving Absolute Speed

When discussing an application’s performance, the word performance is usually synonymous with

speed. You’ll find two types of speed in software development:

l Absolute: Absolute speed is how quickly your application performs a function, such as

running a certain query. Absolute speed can be measured in units of time.

l Perceived: Perceived speed is how end users perceive an application’s performance. This

phenomenon of perceived speed is often the result of visual feedback provided to the user

while the application performs a task. Whereas absolute speed can be measured, per-

ceived speed is very subjective. (For more on perceived speed, see the “Improving

Perceived Speed” section, later in this chapter.)

Among the most important steps for increasing absolute speed are the following:

l Keeping your application in a compiled state: As was discussed in the “Distributing

.accde Files” section, converting your .accdb file to an .accde file is a good way to

ensure that the code is always in a compiled state.

l (^) Organizing your procedures into “smart” modules: As was discussed in the
“Understanding Module Load on Demand” section, separating procedures into modules
based on how frequently they’ll be used is a good approach.
l Opening databases exclusively: You should always open a database exclusively in a
single-user environment. If your database is a standalone application (meaning that nothing
is shared over a network), opening the database in exclusive mode really boosts perfor-
mance. If the database runs on a network and is shared by multiple users, the database