Reviewed by Aditya Kumar · Last reviewed 2026-03-24
**Architectural Logic**: Distribution determines data placement—affects join and aggregation performance. **EVEN**: Round-robin; default; when no clear join key. **KEY**: By distribution key; co-locates same key; use for join key. **ALL**: Full copy on each node; for small...
Architectural Logic: Distribution determines data placement—affects join and aggregation performance. EVEN: Round-robin; default; when no clear join key. KEY: By distribution key; co-locates same key; use for join key. ALL: Full copy on each node; for small dimension tables. Choose KEY: Large fact–fact or fact–dimension joins on same key. Choose ALL: Small dimensions joined to large facts (avoids broadcast). Choose EVEN: No join benefit. Scalability: Poor distribution = skew and slow queries. Best Practice: Distribute fact by common join key; use ALL for small dims; analyze query patterns.
Red Flag: EVEN for fact table joined to dimension on customer_id—massive shuffle. Pro-Move: KEY on fact join key; ALL for dim_product (small); cite skew detection and fix.
According to DataEngPrep.tech, this is one of the most frequently asked SQL interview questions, reported at 1 company. DataEngPrep.tech maintains an editor-reviewed database of 1,863 data engineering interview questions across 7 categories.