About lockTree

When writes hang, run one query on pg_stat_activity with pg_blocking_pids(), paste the result (CSV, tab-separated, JSON or psql's table output) and see the blocking tree: the root blocker at the top, every waiting session under the one it waits for, the lock mode each wants and on which table, how long each has waited and how long the root's transaction has been open. It writes the line to run on the root: pg_terminate_backend for a session idle in transaction (cancelling does nothing there), pg_cancel_backend first for one that is still running. It warns when an ALTER TABLE waiting for its lock has queued every other query behind it, and when sessions wait on each other. Runs in your browser.

Runs entirely in your browser: your SQL and files are not uploaded. Signed-in members can keep a history of runs and results.