Definition
Deliberately duplicating data across rows/tables so reads avoid expensive joins.
How it works
Trades write complexity and storage for read speed: store the data the way a query needs it (precomputed, pre-joined). Standard in NoSQL and read-heavy paths. The cost is keeping the copies in sync on every write — easy to introduce drift, so it's a tool, not a default.
Common questions
What is Denormalization?
Deliberately duplicating data across rows/tables so reads avoid expensive joins.
How does Denormalization work?
Trades write complexity and storage for read speed: store the data the way a query needs it (precomputed, pre-joined). Standard in NoSQL and read-heavy paths. The cost is keeping the copies in sync on every write — easy to introduce drift, so it's a tool, not a default.
What is Denormalization used for in system design?
Trades write complexity and storage for read speed: store the data the way a query needs it (precomputed, pre-joined). Standard in NoSQL and read-heavy paths. The cost is keeping the copies in sync on every write — easy to introduce drift, so it's a tool, not a default.