Querycairn
Import PostgreSQL EXPLAIN JSON offline, compare estimated and actual rows, trace loops and predicates, and turn plan evidence into review actions.
Focused field tools
Read scans, joins, sorts, aggregates, materialization, and parallel nodes as a tree.
Compare planned and actual rows at each node, not just the root.
Multiply per-loop work and recognize nested-loop amplification.
Separate index conditions, filters, join filters, and rows removed.
Review freshness, targets, correlation, skew, extended statistics, and parameters.
Consider selectivity, order, included data, write cost, and real workload.
Querycairn interprets recorded PostgreSQL plan fields and entered context; it does not connect to a database, execute SQL, recommend an index automatically, or prove a change is safe. EXPLAIN ANALYZE executes the statement. Use controlled data, representative parameters, and expert review.