Wrapper

Details

Last Updated on Saturday, 25 February 2012 20:59

Basically a wrapper is something that allows a (java) client to access to a source so a Wrapper can be described with a simple (Java) interface.

A wrapper is basically able to perform 2 tasks:

1. the source introspection: this describes the source "schema" in a MOMIS way, using both ODLi3 and an XML description.
2. the source querying: the wrapper (by the interface WrapperRS) enables a client to access data through a Result Set, that data resulting from a query are accessible as cursor on a table. Operation allowed are to get the numeber of selected columns, get value of a given column and move the cursor on the next row of the table.

Bibliografia di base:

• Documentazione di Momis sui wrapper
• Mary Tork Roth, Peter M. Schwarz: Don't Scrap It, Wrap It! A Wrapper Architecture for Legacy Data Sources. VLDB '97