connection node_2; connection node_1; connection node_1; CREATE TABLE ten (f1 INTEGER not null primary key) Engine=InnoDB; INSERT INTO ten VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10); CREATE TABLE t1 (f1 INTEGER NOT NULL PRIMARY KEY) Engine=InnoDB; INSERT INTO t1 SELECT f1 FROM ten ORDER BY RAND(); connection node_2; UPDATE IGNORE t1 SET f1 = FLOOR(1 + (RAND() * 10)) ORDER BY RAND() LIMIT 5; connection node_1; sum_matches 1 max_matches 1 DROP TABLE t1; CREATE TABLE t2 (f1 INTEGER) Engine=InnoDB; INSERT INTO t2 SELECT f1 FROM ten ORDER BY RAND(); connection node_2; UPDATE IGNORE t2 SET f1 = FLOOR(1 + (RAND() * 10)) ORDER BY RAND() LIMIT 5; connection node_1; sum_matches 1 DROP TABLE t2; DROP TABLE ten;