R: Data Analysis and Visualization

Data integration

Data integration combines data from multiple sources to form a coherent data store. The common issues here are as follows:

• Heterogeneous data: This has no common key
• Different definition: This is intrinsic, that is, same data with different definition, such as a different database schema
• Time synchronization: This checks if the data is gathered under same time periods
• Legacy data: This refers to data left from the old system
• Sociological factors: This is the limit of data gathering

There are several approaches that deal with the above issues:

• Entity identification problem: Schema integration and object matching are tricky. This referred to as the entity identification problem.
• Redundancy and correlation analysis: Some redundancies can ...