Interview Question

What is denormalization?

Denormalization trades simpler reads for added consistency work.

💡 Concept ✅ Quick Revision 🗃️ SQL

Answer

Denormalization deliberately stores redundant or derived data to serve a measured need. • It can reduce joins or repeated calculations for some reads. • Writes must keep duplicated values consistent. • It should follow evidence, ownership rules, and a repair strategy.

💡 SQL Example

ALTER TABLE orders ADD COLUMN item_count integer NOT NULL DEFAULT 0;

Result

ALTER TABLE

⚡ Quick Revision

Denormalization trades simpler reads for added consistency work.