About the Embedded PL/SQL Gateway in Oracle APEX
http://oracleapexonlinetraining.blogspot.com/2016/02/about-embedded-plsql-gateway.html
The embedded PL/SQL gateway installs with Oracle Database 11g. It provides the Oracle database with a Web server and also the necessary infrastructure to create dynamic applications. The embedded PL/SQL gateway runs in the Oracle XML DB HTTP server in the Oracle database and includes the core features of mod_plsql. The following graphic illustrates the Oracle Application Express architecture using the embedded PL/SQL gateway.
As shown in the previous graphic, the embedded PL/SQL gateway is a simple two tier architecture and consists of these components: a Web browser and an Oracle database, containing the embedded PL/SQL and Oracle Application Express.
Advantages of the embedded PL/SQL gateway:
A) Security Considerations When Using the Embedded PL/SQL Gateway
The embedded PL/SQL gateway runs in the database as part of the XML DB HTTP Protocol Listener. The XML DB HTTP Protocol Listener and embedded PL/SQL gateway provides the equivalent core features of Oracle HTTP Server and mod_plsql. Because the HTTP Listener runs in the same database where Oracle Application Express is installed, it is not possible to separate the HTTP listener from the database. For this reason, it is not recommended to use the embedded PL/SQL gateway for applications that run on the Internet. Additionally, the embedded PL/SQL gateway does not provide the same flexibility of configuration and detailed logging as Oracle HTTP Server with mod_plsql.
B) Where Images Are Stored When Using the Embedded PL/SQL Gateway
When running Oracle Application Express with the embedded PL/SQL gateway, images are stored directly in the database within the Oracle XML DB repository. You can access images by using the WebDAV feature of Oracle XML DB or by using FTP.
C) Selecting an HTTP Server in an Oracle RAC Environment
When running Oracle Application Express in an Oracle Real Application Clusters (Oracle RAC) environment, Oracle recommends that you use Oracle HTTP Server with mod_plsql Oracle HTTP Server with mod_plsql permits you to specify a connection in the service name format, so that one HTTP Server can access all nodes.
Oracle recommends that you do not select the embedded PL/SQL gateway option for Oracle RAC installations. The embedded PL/SQL gateway uses an HTTP Server built into the database instance, and because of this, it does not take advantage of the Oracle RAC shared architecture.
Advantages of the embedded PL/SQL gateway:
- Ease of configuration
- Included in the database
- No separate server installation
A) Security Considerations When Using the Embedded PL/SQL Gateway
The embedded PL/SQL gateway runs in the database as part of the XML DB HTTP Protocol Listener. The XML DB HTTP Protocol Listener and embedded PL/SQL gateway provides the equivalent core features of Oracle HTTP Server and mod_plsql. Because the HTTP Listener runs in the same database where Oracle Application Express is installed, it is not possible to separate the HTTP listener from the database. For this reason, it is not recommended to use the embedded PL/SQL gateway for applications that run on the Internet. Additionally, the embedded PL/SQL gateway does not provide the same flexibility of configuration and detailed logging as Oracle HTTP Server with mod_plsql.
B) Where Images Are Stored When Using the Embedded PL/SQL Gateway
When running Oracle Application Express with the embedded PL/SQL gateway, images are stored directly in the database within the Oracle XML DB repository. You can access images by using the WebDAV feature of Oracle XML DB or by using FTP.
C) Selecting an HTTP Server in an Oracle RAC Environment
When running Oracle Application Express in an Oracle Real Application Clusters (Oracle RAC) environment, Oracle recommends that you use Oracle HTTP Server with mod_plsql Oracle HTTP Server with mod_plsql permits you to specify a connection in the service name format, so that one HTTP Server can access all nodes.
Oracle recommends that you do not select the embedded PL/SQL gateway option for Oracle RAC installations. The embedded PL/SQL gateway uses an HTTP Server built into the database instance, and because of this, it does not take advantage of the Oracle RAC shared architecture.
