Functional Dependency and Normalization¶

Data redundancy causes update anomalies; organizing data by functional dependencies (where one attribute uniquely determines another) eliminates redundancy while preserving information.

Tension Addressed¶

Normalization vs. Query Performance

Recognizable As¶

Tables where non-key attributes depend only on the full key; elimination of repeated data groups; decomposition of large tables into smaller ones with foreign key relationships

Canonical Sources¶

Codd, "A Relational Model of Data for Large Shared Data Banks" (1970); Date, "An Introduction to Database Systems" (multiple editions)

Transfers To¶

Configuration management (single source of truth), API design (canonical representations), document structure (avoiding nested duplication)

Normalization through 3NF addresses specific anomalies: 1NF eliminates repeating groups, 2NF removes partial dependencies (attributes depending on part of a composite key), 3NF removes transitive dependencies (attributes depending on non-key attributes). Each level trades join complexity for data integrity.