Understand query performance
Read execution plans and compare snapshots you deliberately capture.
Start with EXPLAIN
Open a query and choose Query → Explain Query, or press Shift–Command–E. The plan view helps you inspect operations, estimates, and likely bottlenecks in plain language. Compare estimates with actual measurements before deciding on a change.
EXPLAIN ANALYZE actually executes the statement. Choose Explain Analyze… only when execution is appropriate for the selected database and query. It can perform writes or invoke side effects; do not treat it as a harmless preview.
Compare captured trends
Open Query → Performance Trends… or the performance toolbar button. Where pg_stat_statements is installed and your role can read it, capture snapshots and compare them later. Captures happen when you request them; Knowhere is not a continuous background monitoring service.
A comparison depends on the available snapshots, statistics resets, and query workload. No app can reconstruct historical measurements that were never captured. Review execution counts and total work alongside mean execution time.
Test an index idea
Hypothetical-index exploration requires the optional HypoPG extension and suitable database permissions. It lets the planner consider an index definition without building a physical index. A planner estimate is not a measured speedup, and hypothetical indexes do not accelerate real query execution.
Review any suggested index against write overhead, storage, existing indexes, and representative plans. Creating a real index is an explicit database change. Knowhere does not silently install extensions or create suggested indexes.
Missing extensions
You can still connect, browse, write SQL, and use ordinary execution plans without pg_stat_statements or HypoPG. Ask your database administrator about optional extension availability; managed providers may restrict installation or the statistics visible to your role.