Answer by Bob Lloyd
PRPC stores work objects in a standard relational database table. By default, the value of all properties are stored in a BLOB (Binary Large Object) column. If an outside tool wants to access some of these properties in the database, a system administrator can expose specific properties by creating columns in the work table that match property names. PRPC will then replicate those properties from the BLOB into the newly created columns.

Crystal Reports just needs to access the table (typically using a JDBC connection) to be able to read the data, as it does with any other database table.

Specifics on exposing database columns are discussed in the System Administration course. You can also refer to the PDN article How to expose a work object property as a column and update data views for more information.