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62c7bd31c8
They share the same locking namespace with the existing session-level advisory locks, but they are automatically released at the end of the current transaction and cannot be released explicitly via unlock functions. Marko Tiikkaja, reviewed by me.
146 lines
4 KiB
PL/PgSQL
146 lines
4 KiB
PL/PgSQL
--
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-- ADVISORY LOCKS
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--
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BEGIN;
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SELECT
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pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
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pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
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SELECT locktype, classid, objid, objsubid, mode, granted
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FROM pg_locks WHERE locktype = 'advisory'
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ORDER BY classid, objid, objsubid;
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-- pg_advisory_unlock_all() shouldn't release xact locks
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SELECT pg_advisory_unlock_all();
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SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
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-- can't unlock xact locks
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SELECT
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pg_advisory_unlock(1), pg_advisory_unlock_shared(2),
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pg_advisory_unlock(1, 1), pg_advisory_unlock_shared(2, 2);
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-- automatically release xact locks at commit
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COMMIT;
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SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
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BEGIN;
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-- holding both session and xact locks on the same objects, xact first
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SELECT
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pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
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pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
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SELECT locktype, classid, objid, objsubid, mode, granted
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FROM pg_locks WHERE locktype = 'advisory'
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ORDER BY classid, objid, objsubid;
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SELECT
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pg_advisory_lock(1), pg_advisory_lock_shared(2),
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pg_advisory_lock(1, 1), pg_advisory_lock_shared(2, 2);
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ROLLBACK;
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SELECT locktype, classid, objid, objsubid, mode, granted
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FROM pg_locks WHERE locktype = 'advisory'
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ORDER BY classid, objid, objsubid;
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-- unlocking session locks
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SELECT
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pg_advisory_unlock(1), pg_advisory_unlock(1),
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pg_advisory_unlock_shared(2), pg_advisory_unlock_shared(2),
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pg_advisory_unlock(1, 1), pg_advisory_unlock(1, 1),
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pg_advisory_unlock_shared(2, 2), pg_advisory_unlock_shared(2, 2);
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SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
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BEGIN;
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-- holding both session and xact locks on the same objects, session first
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SELECT
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pg_advisory_lock(1), pg_advisory_lock_shared(2),
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pg_advisory_lock(1, 1), pg_advisory_lock_shared(2, 2);
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SELECT locktype, classid, objid, objsubid, mode, granted
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FROM pg_locks WHERE locktype = 'advisory'
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ORDER BY classid, objid, objsubid;
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SELECT
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pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
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pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
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ROLLBACK;
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SELECT locktype, classid, objid, objsubid, mode, granted
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FROM pg_locks WHERE locktype = 'advisory'
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ORDER BY classid, objid, objsubid;
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-- releasing all session locks
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SELECT pg_advisory_unlock_all();
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SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
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BEGIN;
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-- grabbing txn locks multiple times
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SELECT
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pg_advisory_xact_lock(1), pg_advisory_xact_lock(1),
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pg_advisory_xact_lock_shared(2), pg_advisory_xact_lock_shared(2),
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pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock(1, 1),
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pg_advisory_xact_lock_shared(2, 2), pg_advisory_xact_lock_shared(2, 2);
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SELECT locktype, classid, objid, objsubid, mode, granted
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FROM pg_locks WHERE locktype = 'advisory'
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ORDER BY classid, objid, objsubid;
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COMMIT;
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SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
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-- grabbing session locks multiple times
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SELECT
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pg_advisory_lock(1), pg_advisory_lock(1),
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pg_advisory_lock_shared(2), pg_advisory_lock_shared(2),
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pg_advisory_lock(1, 1), pg_advisory_lock(1, 1),
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pg_advisory_lock_shared(2, 2), pg_advisory_lock_shared(2, 2);
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SELECT locktype, classid, objid, objsubid, mode, granted
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FROM pg_locks WHERE locktype = 'advisory'
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ORDER BY classid, objid, objsubid;
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SELECT
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pg_advisory_unlock(1), pg_advisory_unlock(1),
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pg_advisory_unlock_shared(2), pg_advisory_unlock_shared(2),
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pg_advisory_unlock(1, 1), pg_advisory_unlock(1, 1),
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pg_advisory_unlock_shared(2, 2), pg_advisory_unlock_shared(2, 2);
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SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
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-- .. and releasing them all at once
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SELECT
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pg_advisory_lock(1), pg_advisory_lock(1),
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pg_advisory_lock_shared(2), pg_advisory_lock_shared(2),
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pg_advisory_lock(1, 1), pg_advisory_lock(1, 1),
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pg_advisory_lock_shared(2, 2), pg_advisory_lock_shared(2, 2);
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SELECT locktype, classid, objid, objsubid, mode, granted
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FROM pg_locks WHERE locktype = 'advisory'
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ORDER BY classid, objid, objsubid;
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SELECT pg_advisory_unlock_all();
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SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
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