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When using Unique Keys with nullable parts in RBR, the slave can choose the wrong row to update. This happens because a table with an unique key containing nullable parts cannot strictly guarantee uniqueness. As stated in the manual, for all engines, a UNIQUE index allows multiple NULL values for columns that can contain NULL. We fix this at the slave by extending the checks before assuming that the row found through an unique index is is the correct one. This means that when a record (R) is fetched from the storage engine and a key that is not primary (K) is used, the server does the following: - If K is unique and has no nullable parts, it returns R; - Otherwise, if any field in the before image that is part of K is null do an index scan; - If there is no NULL field in the BI part of K, then return R. A side change: renamed the existing test case file and added a test case covering the changes in this patch.
38 lines
1.1 KiB
Text
38 lines
1.1 KiB
Text
stop slave;
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drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
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reset master;
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reset slave;
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drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
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start slave;
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SET SQL_LOG_BIN=0;
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CREATE TABLE t (a int, b int, c int, key(b));
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SET SQL_LOG_BIN=1;
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CREATE TABLE t (a int, b int, c int);
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INSERT INTO t VALUES (1,2,4);
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INSERT INTO t VALUES (4,3,4);
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DELETE FROM t;
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DROP TABLE t;
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stop slave;
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drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
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reset master;
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reset slave;
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drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
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start slave;
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CREATE TABLE t (a int, b int, c int, key(b));
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ALTER TABLE t DISABLE KEYS;
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INSERT INTO t VALUES (1,2,4);
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INSERT INTO t VALUES (4,3,4);
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DELETE FROM t;
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DROP TABLE t;
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stop slave;
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drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
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reset master;
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reset slave;
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drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
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start slave;
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CREATE TABLE t1 (c1 INT NOT NULL, c2 INT NOT NULL, c3 INT, UNIQUE KEY(c1,c3), KEY(c2));
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INSERT INTO t1(c1,c2) VALUES(1,1);
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INSERT INTO t1(c1,c2) VALUES(1,2);
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UPDATE t1 SET c1=1000 WHERE c2=2;
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Comparing tables master:test.t1 and slave:test.t1
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DROP TABLE t1;
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