EADP for WSAD and VA Java

EADP uses a bean implementer class to isolate the persistence mechanisms from the rest of the application environment. With this release, EADP is introducing its own persistence mechanism (EADP Simple Persistence), which runs very efficiently in s server environment without the needless overhead imposed by EJBs. EADP Simple Persistence provides modelling capabilities for importing and exporting schema and defining relationships, so it is even more convenient to use a build time than EJBs. With EADP Simple Persistence, the information about homes and relationships is stored in an easily accessible XML file, and there is no need to generate data access classes. Also, EADP Simple Persistence avoids hydrating beans and relationships when only the key information needs to be used. So it operates much more efficiently than PersistenceBuilder and an order of magnitude more efficiently than EJBs.

Of course, if you are using VisualAge, you can still use EJBs or Persistence Builder. Access classes for EADP can be generated using either EJBs or Persistence Builder. EADP uses Persistence Builder to define relationships that are of special interest (ruler-to-sub-object relationships for complex objects, quick-view relationships for normalized data, and root-to-version relationships for version control). These are given special standardized names so that EADP can hook into the run-time code generated by Persistence Builder or the EJB facility.

EADP's Complex Object support allows the definition of complex object structures within Persistence Builder through the use of special relationships (these are "ruler-to-sub-object" relationships). A sub-object uses the relationship to its ruler as a part of its primary key. In database terms, this requires that there be a foreign key relationship from the primary key of the ruler to part of the primary key of the sub-object.

Some actions, such as copy and delete, need to cascade throughout the complex object. EADP provides support for this (including additional complex object actions such as Promote and Undo, which are valid only if the data is version-controlled).

EADP also allows the addition of fields in the ruler that present data summarized over its sub-objects (for example, the cost of a purchase order, summarized by adding up the cost of each line item).

Although EADP uses an object model for the results of its queries, this model is flexible enough to allow the use of joins when appropriate, to run SQL functions such as COUNT, and to process mass updates or deletions directly through SQL when this is the right thing to do.

EADP provides a hyper-scrolling capability that allows scrolling directly to page 200 (for example) out of 500 pages returned from a search. Only a few records (the default is 200 rows) are kept in memory at any given time.

The document architecture in EADP takes full advantage of complex object and quick view relationships to glue the pieces of a document together and to match the document data with its descriptor data.

Neither Persistence Builder nor EJBs are suitable "as-is" for use in a WebSphere application. EADP adds the function necessary for handlling large databases and for operating reliably in a clustered WebSphere environment.

EADP document-level security provides security restrictions on access by individual or group. The security restrictions can be to a certain type of table, to individual rows within that table, or to types of rows (the last is useful if the same table contains different types of documents and some groups of users can see only some types of documents). This document-level security is nearly equivalent to the security features available in the Lotus Notes client.

A sample content management application is provided in this package. There is also a base document application that provides the basic classes necessary for creating your own document applications.