System information

9
CONFIGURING AND ADMINISTERING COLDFUSION 9
Using the ColdFusion Administrator
Last updated 2/21/2012
Important: Adobe recommends that you do not store client variables in the registry because it can critically degrade
performance of the server. If you use the registry to store client variables, you allocate sufficient memory and disk
space.
To override settings specified in the Client Variables page, use the Application.cfc file or the cfapplication tag. For
more information, see the Developing ColdFusion Applications.
The following table compares the client variable storage options:
Migrating client variable data
To migrate your client variable data to another data source, determine th----e structure of the database tables that store
this information. Client variables stored externally use two simple database tables, as shown in the following tables:
Storage type Advantages Disadvantages
Data source
• Can use existing data source
• Portable: not tied to the host system or
operating system
• Requires database transaction to read/write variables
• More complex to implement
Browser cookies
• Simple implementation
• Good performance
• Can be set to expire automatically
• Client-side control
• Users can configure browsers to disallow cookies
• Cookie data is limited to 4-KB
• Netscape Navigator allows only 20 cookies from one host;
ColdFusion uses three cookies to store read-only data,
leaving only 17 cookies available
System registry
• Simple implementation
• Good performance
• Registry can be exported easily to other systems
• Server-side control
• Possible restriction of the registry’s maximum size limit in
Windows in the Control Panel
• Integrated with the host system: not practical for
clustered servers
• Not available for UNIX
• Applicable only for Windows
CDATA Table
Column Data type
cfid CHAR(64), TEXT, VARCHAR, or equivalent
app CHAR(64), TEXT, VARCHAR, or equivalent
data MEMO, LONGTEXT, LONG VARCHAR, or equivalent
CGLOBAL Table
Column Data type
cfid CHAR(64), TEXT, VARCHAR, or equivalent
data MEMO, LONGTEXT, LONG VARCHAR, or equivalent
lvisit TIMESTAMP, DATETIME, DATE, or equivalent