intermediatePerformance — EXPLAIN ANALYZE, Partitioning & Sharding

How do you read an EXPLAIN ANALYZE output? What are the key things to look for?

Key things to examine: 1) Seq Scan on large tables: a Seq Scan on a million-row table means no index is being used. Candidate for indexing. 2) Actual rows vs estimated rows: if actual=10000 and estimated=10, the planner used a bad plan. Run ANALYZE to update statistics. 3) Execution time vs planning time: if planning takes longer than execution, the query is very fast. If execution is long, find t

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