Chapter 11: Reporting and Batch Processing

Overview

Up To This Point in the book ”and although you may not have realized it ”our focus has been on online transaction processing (OLTP) applications. We've discussed how to create business objects that model entities within our problem domain, and how to use them to retrieve and update data from a data store. This is all very important, and most real-world applications have a great deal of OLTP functionality.

However, most real-world applications also have functionality that is not interactive, and that's the focus of this final chapter. For example, most applications provide some form of report generation. End users often want to view or print lists of data or groups of data, or to have huge amounts of data compressed into summaries. Retrieving and manipulating all the data required to generate reports is often very complex and resource intensive .

Similarly, many applications need to do batch processing, which typically also involves manipulation of large amounts of data as part of a single process. For instance, most sales systems have end-of-day processing, where they take all the sales transactions for the day and post that data into the accounting system. Most manufacturing systems have daily or weekly processing that recalculates projected manufacturing schedules based on future sales orders.

In truth, it's the rare enterprise application that doesn't have some large reporting or processing task that runs against large amounts of data. This type of task is fundamentally different from OLTP. An OLTP task typically involves the retrieval and update of small, discrete amounts of data. Each such update is relatively isolated from any other OLTP task.

When we discuss report generation or batch processing, however, we're talking about a single task that reads and/or updates large sets of data entirely as part of one large process. Whereas the time to do an OLTP task is often measured in milliseconds , the time to generate a report or run a batch process is often measured in minutes, and sometimes even hours.