A schema mapping is a specification that describes how data structured under one schema (the source schema) is to be transformed into data structured under a different schema (the...
A schema mapping is a specification that describes how data structured under one schema (the source schema) is to be transformed into data structured under a different schema (the...
Ronald Fagin, Phokion G. Kolaitis, Lucian Popa, Wa...
Data exchange is the problem of taking data structured under a source schema and creating an instance of a target schema. Given a source instance, there may be many solutions ? ta...
We study the problem of answering queries through a target schema, given a set of mappings between one or more source schemas and this target schema, and given that the data is at...