Oracle Application Express - Disadvantages

Disadvantages

• As an application framework, it can be difficult to customize an application outside of a set of expectations about how an APEX application is supposed to operate. However, given that pages are built from customizable templates, anything that is possible to achieve with HTML, CSS and Javascript is also theoretically possible to achieve with APEX, although it requires more work than using the built-in templates.
• Large installation size. The unzipped installation files for Apex 4.1 that includes 9 different languages for the "Application Builder" interface is 747 megabytes. The English-only version is 147 megabytes. Apex is installed on the database server; developers and users only need a web browser to build and use applications.
• Limited debugging facilities. The APEX framework logs page events in a database table and the log can be inspected by the developer. The developer can also add his own messages to the log during page rendering. Javascript must be debugged using standard development tools such as Firebug.
• Primary keys can be at most two separate fields. However since version 4.1 Application Express supports the use of ROWID for updates, inserts and deletes as an alternative to specifying primary keys. Prior to version 4.1 APEX assumed by default that all tables would use generated keys such as from sequences or triggers, therefore, if a table had more than two key columns then the default DML processes could not be used.
• Pages in APEX can display at most 200 items and forms cannot handle more than 200 database items. Compare this to the Oracle Database where tables can have up to 1000 columns. Pages must be designed to work around this limitation, for example by using multiple pages, tabular forms, or Ajax for on-demand updates.
• APEX applications are created using Oracle's own tools and only can be hosted in an Oracle database, making an implementer susceptible to vendor lock-in.
• Very few webhosts offer APEX (Oracle Database) on their hosting service package (most of them offer PHP + MySQL or ASP + Microsoft SQL Server). As a result, APEX applications are limited in their choice of webhosts.