Databases Reference
In-Depth Information
you ask other Cascading developers for help debugging an issue, don't be surprised
when their first request is to see your app's flow diagram.
Figure 1-4. Annotated flow diagram for
“Example 2: The Ubiquitous Word Count”
From a high-level perspective,
“Example 2: The Ubiquitous Word Count”
differs from
“Example 1: Simplest Possible App in Cascading”
in two ways:
• Source and sink taps are more specific.
• Three operators have been added to the pipe assembly.
Although several lines of Java source code changed, in pattern language terms we can
express the difference between the apps simply as those two points. That's a powerful
benefit of using the “plumbing” metaphor.
First let's consider how the source and sink taps were redefined to be more specific.
Instead of simply describing a generic “Source” or “File A,” now we've defined the source
