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	The problem is that the internal variable used to specify a transaction with consistent read was being used outside the processing context of a START TRANSACTION WITH CONSISTENT SNAPSHOT statement. The practical consequence was that a consistent snapshot specification could leak to unrelated transactions on the same session. The solution is to ensure a consistent snapshot clause is only relied upon for the START TRANSACTION statement. This is already fixed in a similar way on 6.0.
		
			
				
	
	
		
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			80 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
--source include/have_innodb.inc
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# Save the initial number of concurrent sessions
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--source include/count_sessions.inc
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--disable_warnings
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DROP TABLE IF EXISTS t1;
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--enable_warnings
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--echo # Establish connection con1 (user=root)
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connect (con1,localhost,root,,);
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--echo # Establish connection con2 (user=root)
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connect (con2,localhost,root,,);
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--echo ### Test 1:
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--echo ### - While a consistent snapshot transaction is executed,
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--echo ###   no external inserts should be visible to the transaction.
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--echo # Switch to connection con1
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connection con1;
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CREATE TABLE t1 (a INT) ENGINE=innodb;
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START TRANSACTION WITH CONSISTENT SNAPSHOT;
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--echo # Switch to connection con2
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connection con2;
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INSERT INTO t1 VALUES(1);
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--echo # Switch to connection con1
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connection con1;
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SELECT * FROM t1; # if consistent snapshot was set as expected, we
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# should see nothing.
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COMMIT;
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--echo ### Test 2:
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--echo ### - For any non-consistent snapshot transaction, external
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--echo ###   committed inserts should be visible to the transaction.
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DELETE FROM t1;
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START TRANSACTION; # Now we omit WITH CONSISTENT SNAPSHOT
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--echo # Switch to connection con2
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connection con2;
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INSERT INTO t1 VALUES(1);
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--echo # Switch to connection con1
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connection con1;
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SELECT * FROM t1; # if consistent snapshot was not set, as expected, we
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# should see 1.
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COMMIT;
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--echo ### Test 3:
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--echo ### - Bug#44664: valgrind warning for COMMIT_AND_CHAIN and ROLLBACK_AND_CHAIN
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--echo ###   Chaining a transaction does not retain consistency level.
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START TRANSACTION WITH CONSISTENT SNAPSHOT;
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DELETE FROM t1;
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COMMIT WORK AND CHAIN;
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--echo # Switch to connection con2
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connection con2;
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INSERT INTO t1 VALUES(1);
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--echo # Switch to connection con1
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connection con1;
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SELECT * FROM t1; # if consistent snapshot was not set, as expected, we
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# should see 1.
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COMMIT;
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--echo # Switch to connection default + close connections con1 and con2
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connection default;
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disconnect con1;
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disconnect con2;
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DROP TABLE t1;
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# End of 4.1 tests
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# Wait till all disconnects are completed
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--source include/wait_until_count_sessions.inc
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