connection node_2;
connection node_1;
#
# 1 . LOCK TABLE and INSERT
#
connection node_1;
CREATE TABLE t1 (
id varchar(100 ),
PRIMARY KEY (id)) engine=innodb;
CREATE TABLE t2 (
id varchar(100 ) , a varchar(100 ),
PRIMARY KEY (id,a),
KEY a (a),
CONSTRAINT FOREIGN KEY (a) REFERENCES t1 (id)
) ENGINE=InnoDB;
CREATE TABLE t3 (
a varchar(100 ),
b varchar(100 ) ,
PRIMARY KEY (a, b),
CONSTRAINT FOREIGN KEY (a) REFERENCES t2 (a)
) ENGINE=InnoDB;
LOCK TABLES t1 WRITE;
INSERT INTO t1 VALUES ('a' );
UNLOCK TABLES;
connection node_2;
select * from t1;
id
a
connection node_1;
select * from t1;
id
a
DROP TABLE t3, t2, t1;
#
# 2 . FLUSH TABLES WITH READ LOCK and INSERT
#
connection node_1;
CREATE TABLE t1 (
id varchar(100 ),
PRIMARY KEY (id)) engine=innodb;
CREATE TABLE t2 (
id varchar(100 ) , a varchar(100 ),
PRIMARY KEY (id,a),
KEY a (a),
CONSTRAINT FOREIGN KEY (a) REFERENCES t1 (id)
) ENGINE=InnoDB;
CREATE TABLE t3 (
a varchar(100 ),
b varchar(100 ) ,
PRIMARY KEY (a, b),
CONSTRAINT FOREIGN KEY (a) REFERENCES t2 (a)
) ENGINE=InnoDB;
FLUSH TABLES WITH READ LOCK;
INSERT INTO t1 VALUES ('a' );
ERROR HY000: Can't execute the query because you have a conflicting read lock
UNLOCK TABLES;
connection node_2;
select * from t1;
id
connection node_1;
select * from t1;
id
DROP TABLE t3, t2, t1;
Messung V0.5 in Prozent C=33 H=100 G=74
¤ Dauer der Verarbeitung: 0.11 Sekunden
(vorverarbeitet am 2026-10-10)
¤
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