TOAST stands for The Oversized-Attribute Storage Technique.
PostgreSQL uses a fixed page size (commonly 8 kB), and does not allow tuples to span multiple pages. Therefore, it is not possible to store very large field values directly. To overcome this limitation, large field values are compressed and/or broken up into multiple physical rows. Read More
Here is a script to check table level locks
SELECT act1.query as blocking_query, act2.query as blocked_query, l1.pid AS blocked_pid, l2.pid AS blocking_pid, l1.relation :: regclass FROM pg_locks l1, pg_locks l2, pg_stat_activity act1, pg_stat_activity act2 WHERE l1.granted = true AND l2.granted = false AND l1.pid = act1.pid AND l2.pid = act2.pid AND l1.relation = l2.relation;
Cheers!
Here is a script to check which query is blocking who.
SELECT bl.pid AS blocked_pid, a.usename AS blocked_user, ka.query AS current_or_recent_statement_in_blocking_process, ka.state AS state_of_blocking_process, now() - ka.query_start AS blocking_duration, kl.pid AS blocking_pid, ka.usename AS blocking_user, a.query AS blocked_statement, now() - a.query_start AS blocked_duration FROM pg_catalog.pg_locks bl JOIN pg_catalog.pg_stat_activity a ON a.pid = bl.pid JOIN pg_catalog.pg_locks kl ON kl.transactionid = bl.transactionid AND kl.pid != bl.pid JOIN pg_catalog.pg_stat_activity ka ON ka.pid = kl.pid WHERE NOT bl.GRANTED;
Cheers!
