38 lines
940 B
Python
38 lines
940 B
Python
# Test NOWAIT with multixact locks.
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setup
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{
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CREATE TABLE foo (
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id int PRIMARY KEY,
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data text NOT NULL
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);
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INSERT INTO foo VALUES (1, 'x');
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}
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teardown
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{
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DROP TABLE foo;
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}
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session s1
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setup { BEGIN; }
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step s1a { SELECT * FROM foo FOR SHARE NOWAIT; }
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step s1b { COMMIT; }
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session s2
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setup { BEGIN; }
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step s2a { SELECT * FROM foo FOR SHARE NOWAIT; }
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step s2b { SELECT * FROM foo FOR UPDATE NOWAIT; }
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step s2c { COMMIT; }
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# s1 and s2 both get SHARE lock, creating a multixact lock, then s2
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# tries to upgrade to UPDATE but aborts because it cannot acquire a
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# multi-xact lock
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permutation s1a s2a s2b s1b s2c
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# the same but with the SHARE locks acquired in a different order, so
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# s2 again aborts because it can't acquired a multi-xact lock
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permutation s2a s1a s2b s1b s2c
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# s2 acquires SHARE then UPDATE, then s1 tries to acquire SHARE but
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# can't so aborts because it can't acquire a regular lock
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permutation s2a s2b s1a s1b s2c
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