Summary
This chapter discussed various organizational processes used to prepare data for analysis. When used in computer programs, each data value is assigned a data type, which characterizes the data and defines the kind of operations that can be performed upon it.
When stored in a relational database, data is organized into tables, in which each row corresponds to one data point, and where all the data in each column corresponds to a single field of a specified type. The key field(s) has unique values, which allows indexed searching.
A similar viewpoint is the organization of data into key-value pairs. As in relational database tables, the key fields must be unique. A hash table implements the key-value paradigm with a hash function that determines where the key's associated data is stored.
Data files are formatted according to their file type's specifications. The comma-separated value type (CSV) is one of the most common. Common structured data file types include XML and JSON.
The information...
