9

Wrappers

Wrappers are the components of a data integration system that communicate with the data sources. The wrapper’s task involves sending queries from the higher levels of the data integration system to the sources and then converting the replies to a format that can be manipulated by the query processor. The complexity of the wrapper depends on the nature of the data source. In the simplest case, if the data source is a relational database system, then the task of the wrapper is rather simple and can involve merely interacting with a JDBC driver (which, admittedly, can often be harder than you would expect!). In more complex cases, the wrapper needs to parse semistructured data such as those found on HTML pages and transform them into ...

Get Principles of Data Integration now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.