Reviewed by Aditya Kumar · Last reviewed 2026-03-24
**Logical Plan**: Abstract 'what'—filter, join, aggregate. Independent of execution. Optimizer applies rules (predicate pushdown, constant folding). **Physical Plan**: Concrete 'how'—which join algo (sort-merge, broadcast hash), partitioning, resource allocation. Cost-based...
Logical Plan: Abstract 'what'—filter, join, aggregate. Independent of execution. Optimizer applies rules (predicate pushdown, constant folding).
Physical Plan: Concrete 'how'—which join algo (sort-merge, broadcast hash), partitioning, resource allocation. Cost-based choices.
Why Both: Separation enables optimization without locking to implementation. Tuning: understand both to debug skew, slow stages.
Pro-Move: 'When a query was slow, I checked the physical plan—found BroadcastHashJoin wasn't used due to stats; fixed with ANALYZE.'
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