pgrowlocks The pgrowlocks module provides a function to show row locking information for a specified table. pgrowlocks(text) returns setof record The parameter is the name of a table. The result is a set of records, with one row for each locked row within the table. The output columns are: Name Type Description locked_row tid Tuple ID (TID) of locked row lock_type text Shared for shared lock, or Exclusive for exclusive lock locker xid Transaction ID of locker, or multixact ID if multi-transaction multi boolean True if locker is a multi-transaction xids xid[] Transaction IDs of lockers (more than one if multi-transaction) pids integer[] Process IDs of locking backends (more than one if multi-transaction) pgrowlocks takes AccessShareLock for the target table and reads each row one by one to collect the row locking information. This is not very speedy for a large table. Note that: If the table as a whole is exclusive-locked by someone else, pgrowlocks will be blocked. pgrowlocks is not guaranteed to produce a self-consistent snapshot. It is possible that a new row lock is taken, or an old lock is freed, during its execution. pgrowlocks does not show the contents of locked rows. If you want to take a look at the row contents at the same time, you could do something like this: SELECT * FROM accounts AS a, pgrowlocks('accounts') AS p WHERE p.locked_row = a.ctid; Be aware however that (as of PostgreSQL 8.3) such a query will be very inefficient. test=# SELECT * FROM pgrowlocks('t1'); locked_row | lock_type | locker | multi | xids | pids ------------+-----------+--------+-------+-----------+--------------- (0,1) | Shared | 19 | t | {804,805} | {29066,29068} (0,2) | Shared | 19 | t | {804,805} | {29066,29068} (0,3) | Exclusive | 804 | f | {804} | {29066} (0,4) | Exclusive | 804 | f | {804} | {29066} (4 rows) Tatsuo Ishii