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"Storage engine handles GROUP BY" optimization in Sequence SE returns incorrect value for COUNT(NULL):
MariaDB [test]> select * from seq_1_to_3;
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+-----+
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| seq |
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+-----+
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| 1 |
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| 2 |
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| 3 |
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+-----+
|
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MariaDB [test]> select count(NULL) from seq_1_to_3;
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+-------------+
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| count(NULL) |
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+-------------+
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| 3 |
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+-------------+
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This is an incorrect result. For comparison:
create table t100 (a int);
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insert into t100 values (1),(2),(3);
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select count(NULL) from t100;
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+-------------+
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| count(NULL) |
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+-------------+
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| 0 |
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+-------------+
|
|