citus/src/backend/distributed/sql/udfs/citus_blocking_pids/12.2-1.sql

35 lines
1.2 KiB
PL/PgSQL

DROP FUNCTION pg_catalog.citus_blocking_pids;
CREATE FUNCTION pg_catalog.citus_blocking_pids(pBlockedPid integer)
RETURNS int4[] AS $$
DECLARE
mLocalBlockingPids int4[];
mRemoteBlockingPids int4[];
mLocalGlobalPid int8;
BEGIN
SELECT pg_catalog.old_pg_blocking_pids(pBlockedPid) INTO mLocalBlockingPids;
IF (array_length(mLocalBlockingPids, 1) > 0) THEN
RETURN mLocalBlockingPids;
END IF;
-- pg says we're not blocked locally; check whether we're blocked globally.
SELECT global_pid INTO mLocalGlobalPid
FROM get_all_active_transactions() WHERE process_id = pBlockedPid;
SELECT array_agg(global_pid) INTO mRemoteBlockingPids FROM (
WITH activeTransactions AS (
SELECT global_pid FROM get_all_active_transactions()
), blockingTransactions AS (
SELECT blocking_global_pid FROM citus_internal.global_blocked_processes()
WHERE waiting_global_pid = mLocalGlobalPid
)
SELECT activeTransactions.global_pid FROM activeTransactions, blockingTransactions
WHERE activeTransactions.global_pid = blockingTransactions.blocking_global_pid
) AS sub;
RETURN mRemoteBlockingPids;
END;
$$ LANGUAGE plpgsql;
REVOKE ALL ON FUNCTION citus_blocking_pids(integer) FROM PUBLIC;