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Microsoft Office Access 2003
Tutorial 12 – Managing and Securing a
Database
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Analyze a database's performance
• Analysis tools will help you provide a database
that runs as efficiently as possible.
• The Performance Analyzer will produce a list
of ideas, suggestions, and recommendations.
• However, many of the suggestions and
recommendations can be carried out for you.
• If you decide to allow Access to fix the
problem, you will be able to check the results
by viewing the objects pertaining to the
suggestion.
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The Performance Analyzer dialog box
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The Performance Analyzer
analysis window
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View and print database
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• If you want to print a graphical view of the relationships in your
database, you can have Access print the relationships window.
• This will print exactly what you see when you open this window.
• If you need to have more detailed information about the objects in the
database, you can run the Documenter.
• In the Documenter, you can choose what objects to include in the
Documenter's report and you can make several choices as to what
should be included in the report.
• When you are finished making your selections, you will received a
very detailed report containing Field names, Field types, Field sizes,
relationships with other objects, etc.
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Link a database to a table
in another database
• There will be times when you will want to make an Access
table available to a user for data entry, but you would not
want them to be able to change the structure of your table.
• You can do this by providing a linked table in the database.
• A linked table is a table that is stored in a file outside the
open database.
• Access will be able to update and retrieve records in the
open database but will disallow changes to the structure of
the table.
• When you establish a link to a table in the database, the
linked table shows up on your list of table objects but the
icon looks different.
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The Link Tables dialog box
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Use the Linked Table Manager
• When you link to a table, Access keeps track of where that
table is stored.
• If you move the location of the database to a different
folder, Access won't know where it is.
• You can use the Linked Table Manager to refresh the link
to the table so that Access will be able to find the linked
table.
• In the Linked Table Manger, point to the new location, and
Access will then update the link information.
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The Linked Table Manager dialog box
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Use replication to create a DesignXP
Master and replica of a database
• Sometimes there will be multiple users updating database
data.
• If you gave each one a copy of the database and allowed
them each to make changes in their copy, it would be quite
difficult to pull all the changes together later into a single
database.
• However, replication makes it easy to handle this kind of
activity.
• When you create a replica of a database, you create a
special copy of the database and the original copy becomes
the Design Master of the database.
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Update Design Masters
from replica sets
• The Design Master and all of the replicas that
have been made of it are called the replica set.
• Once you have created a replica set, Access keeps
track of the changes that eventually will be
incorporated into the Design Master.
• Any changes in the data in any replicas can be
updated automatically in the Design Master
through a process called synchronization.
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The Database Window
for a Design Master
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Synchronize the Design Master XP
and replica Data
• When you have a replica set, you can synchronize the records in the
replica database(s) by running the Synchronize Database process.
– When the synchronization process is run, Access will check for changes in
the data in the replica database(s) and, if any, will incorporate those
changes into the Design Master.
• After the synchronization process is complete, you will be able to see
the changes that have been made in the replica database(s) in the
Design Master database.
• When you no longer need the replica(s), you should delete them.
• If there are no replicas being used, you should rename the Design
Master to its original name.
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The Synchronize Database dialog box
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Split a database
• A database developer often will separate the interface to a
database (its queries, forms, and other database objects)
from the actual database data. This is known as splitting
the database.
• The Database Splitter splits the database into two
databases.
• The database that contains the actual data is called the
back-end database.
• The database that contains the other objects is called the
front-end database.
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The Database Splitter dialog box
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Front-end versus back-end database
• The users of the database will work through the front-end
database to add, modify, and delete data in the back-end
database.
• The developer does not make changes to the back-end
database but periodically makes changes to the front-end
database by updating its queries, forms, and reports.
• In a network environment, the back-end database is usually
stored on the network where users can access it.
• The Front-End database is stored on all the user computers,
as it is their interface to the back-end database.
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An illustration of splitting a database
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Set database startup options
• There are several options that can be set to be initiated at
the time the database is opened.
• These options are called Startup Options and can be set by
clicking Tools on the menu bar and then click Startup.
• On this Startup dialog box, you can specify a particular
form you want to display when the database is opened.
• You can also choose from several options related to how
much access users will have to the menu and toolbars.
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The Startup dialog box
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Implement database security
• Databases often have sensitive data that must be
protected.
• Security refers to the protection of a database
against unauthorized access.
• Startup options offer a degree of security but there
is more that you could do to protect the data.
• You can use Encryption, Decryption, and
Passwords to protect your database.
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Encrypt and decrypt a database
• Encryption is a process that will convert the data in a
database to a format that is unreadable.
– If a user is able to gain access to a database that is encrypted, the
data could only be read if it was decrypted
• Decrypting a database is the process of returning the
encrypted data to its original state.
• Another form of security includes the use of passwords.
– Passwords applied to a database makes it impossible to open the
database unless you know the password
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Set and unset a database password
• If data is very important and meant to be viewed only by
authorized users, it is a good idea to assign a password to the
database.
• When you set a password, you usually establish exclusive
access, meaning that only one user can access the database at
a time.
• You can also set the password so that the database is opened
as Read-Only, meaning that no changes can be made to the
database.
• In order to remove the password, you must use the password
to get into the database and unset (or cancel) the password.
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The Set Database Password dialog box
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Implement user-level security
• The security measures discussed in previous sections apply
to all users of the database.
• Sometimes you will want to allow some users access rights
and disallow those rights for other users.
• You can accomplish this by setting user-level security.
• User-level security lets you grant users or groups of users
specific permission to tables, queries, forms, reports, and
macros.
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Assign users permissions to a database
• You can assign each user a set of permissions, which
specify what that particular user has rights to.
• You can specify that a user can modify data or can only
read data.
• You can specify whether the user is allowed to delete data.
• This kind of activity is usually managed by a person
designated as the database administrator, or a group of
people called the database administration (DBA) group.
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Assign group permissions
for multiple users
• The DBA will be responsible for controlling and assigning
permissions to certain users.
• Because there are often groups of people who should have
the same permissions, the DBA can assign permissions to
groups rather than individuals.
• Usually there is a workgroup information file that
maintains group names, user names, passwords, and group
membership information.
• This information is stored in hidden files and is available
only to the DBA.
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An illustration of user-level security
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Use the Security Wizard
to assign permissions
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Protect VBA code from
unauthorized changes
• Database developers often work long, tedious
hours writing VBA code to augment the
functionality of the database.
• Usually, the developer will want to protect the
code from unwarranted changes.
• The code is readily available in the modules of the
database unless the code is converted.
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Create an MDE file
• You can save a database as an MDE file, which compiles
all the VBA code into machine code and removes the VBA
source code.
• The database will still work exactly as it did prior to this
conversion, but no one will be able to alter the code
because they will not be able to get to it.
• In Access 2003, you must make sure the database is in
2002 format before you try to convert it to an MDE file.
• This process is not always necessary and should only be
done if there are many VBA modules in the database and
the code must be protected from changes.
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