Data dictionary
A document that describes each column in a dataset: its name, meaning, data type, allowed values, and units.
It is where you learn that status 3 means suspended, or that weight is in kilograms. Without one, the meaning of a column lives in the memory of whoever built it.
Where it comes up
- Codes without a lookupA column holds short codes such as 3, A, or XR, and the table that says what each code means is not in the file.
- Inconsistent column names across filesFiles that should share one layout name the same column differently, or use the same name for different things.
See also
- MetadataData that describes other data: column names and types, when a file was created, where it came from, and how many rows it holds.
- SchemaThe declared structure of a dataset: its columns, their names and types, and the rules they must satisfy.
- Lookup tableA table that translates codes into their meanings or one set of values into another, such as state abbreviations to state names.