The Oracle ATG Platform provides two options for querying the Oracle Endeca Assembler and MDEX engine:
Invoking the Assembler via a servlet as part of Oracle ATG’s request handling pipeline. This option allows the call to the Assembler to happen early in the page’s life cycle, which is desirable when the bulk of the page’s content is served by the Assembler.
Invoking the Assembler from within a page, using a servlet bean. This option allows the call to the Assembler to occur on a just-in-time basis for the portion of the page that requires Assembler-served content. This approach is desirable when only a small portion of the page requires Assembler content.
The remainder of this chapter provides more detail on both configurations and the components that facilitate them. It includes these sections: