Explain CTE vs Temp Table. What are the differences and use cases?

Architectural Logic: CTE = inline; temp table = materialized—affects performance and reuse. CTE: Scope within query; no persistence; optimizer may inline. Temp Table: Materialized; session scope; can index; statistics available. Use CTE: One-off logic; readability; recursion. Use Temp Table: Multiple references; large intermediate; need indexes. Example: CTE for single-use subquery; temp table for CREATE TEMP TABLE t AS ...; CREATE INDEX ON t(col); then multiple joins. Scalability: Temp table enables index; CTE may duplicate work. Cost: Temp table has storage cost; CTE is compute-only within query. Best Practice: CTE for simplicity; temp table for performance with reuse; check query plan.