Find cardinality misestimates with EXPLAIN ANALYZE on the Join Order Benchmark

Record estimated versus actual rows per plan node for multi-join queries, locate the first large error and test whether statistics or rewrites change the plan.

The exercise happens on Join Order Benchmark + local PostgreSQL. Canonical link: https://github.com/gregrahn/join-order-benchmark. Link check: link responded (5 Oct 2026). Opened from this app 0 times; opening is not counted as an attempt.

Supports: Performance debugging for backend roles and optimizer research preparation.