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+# The example from the paper "A read-only transaction anomaly under snapshot
+# isolation"[1].
+#
+# Here we test that serializable snapshot isolation (SERIALIZABLE) doesn't
+# suffer from the anomaly, because s2 is aborted upon detection of a cycle.
+# In this case the read only query s3 happens to be running in a parallel
+# worker.
+#
+# [1] http://www.cs.umb.edu/~poneil/ROAnom.pdf
+
+setup
+{
+ CREATE TABLE bank_account (id TEXT PRIMARY KEY, balance DECIMAL NOT NULL);
+ INSERT INTO bank_account (id, balance) VALUES ('X', 0), ('Y', 0);
+}
+
+teardown
+{
+ DROP TABLE bank_account;
+}
+
+session s1
+setup { BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE; }
+step s1ry { SELECT balance FROM bank_account WHERE id = 'Y'; }
+step s1wy { UPDATE bank_account SET balance = 20 WHERE id = 'Y'; }
+step s1c { COMMIT; }
+
+session s2
+setup { BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE; }
+step s2rx { SELECT balance FROM bank_account WHERE id = 'X'; }
+step s2ry { SELECT balance FROM bank_account WHERE id = 'Y'; }
+step s2wx { UPDATE bank_account SET balance = -11 WHERE id = 'X'; }
+step s2c { COMMIT; }
+
+session s3
+setup {
+ BEGIN TRANSACTION ISOLATION LEVEL SERIALIZABLE;
+ SET debug_parallel_query = on;
+ }
+step s3r { SELECT id, balance FROM bank_account WHERE id IN ('X', 'Y') ORDER BY id; }
+step s3c { COMMIT; }
+
+# without s3, s1 and s2 commit
+permutation s2rx s2ry s1ry s1wy s1c s2wx s2c s3c
+
+# once s3 observes the data committed by s1, a cycle is created and s2 aborts
+permutation s2rx s2ry s1ry s1wy s1c s3r s3c s2wx