Details
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Bug
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Status: Closed (View Workflow)
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Minor
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Resolution: Fixed
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5.3.11
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None
Description
The following EXPLAIN command from the test case for LP bug #934348
EXPLAIN
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SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a)
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GROUP BY a HAVING a != 'z';
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returns
id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t index idx_a idx_a 4 NULL 1 Using index
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...
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It should return
id select_type table type possible_keys key key_len ref rows Extra
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1 PRIMARY t index idx_a idx_a 4 NULL 3 Using index
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as the number of rows in the table t1 is equal to 3.
Attachments
Activity
| Field | Original Value | New Value |
|---|---|---|
| Description |
The following EXPLAIN command from the test case for LP bug #934348 {code} EXPLAIN SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a) GROUP BY a HAVING a != 'z'; {/code} returns {code} id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t index idx_a idx_a 4 NULL 1 Using index ... {/code} It should return {code} id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t index idx_a idx_a 4 NULL 3 Using index {/code} as the number of rows in the table t1 is equal to 3. |
The following EXPLAIN command from the test case for LP bug #934348 {code} EXPLAIN SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a) GROUP BY a HAVING a != 'z'; {code} returns {code} id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t index idx_a idx_a 4 NULL 1 Using index ... {/code} It should return {code} id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t index idx_a idx_a 4 NULL 3 Using index {/code} as the number of rows in the table t1 is equal to 3. |
| Description |
The following EXPLAIN command from the test case for LP bug #934348 {code} EXPLAIN SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a) GROUP BY a HAVING a != 'z'; {code} returns {code} id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t index idx_a idx_a 4 NULL 1 Using index ... {/code} It should return {code} id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t index idx_a idx_a 4 NULL 3 Using index {/code} as the number of rows in the table t1 is equal to 3. |
The following EXPLAIN command from the test case for LP bug #934348 {code} EXPLAIN SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a) GROUP BY a HAVING a != 'z'; {code} returns {code} id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t index idx_a idx_a 4 NULL 1 Using index ... {code} It should return {code} id select_type table type possible_keys key key_len ref rows Extra 1 PRIMARY t index idx_a idx_a 4 NULL 3 Using index {code} as the number of rows in the table t1 is equal to 3. |
| Priority | Major [ 3 ] | Minor [ 4 ] |
| Fix Version/s | 5.3.13 [ 12602 ] | |
| Fix Version/s | 5.3.12 [ 12000 ] |
| Workflow | defaullt [ 25805 ] | MariaDB v2 [ 45963 ] |
| Workflow | MariaDB v2 [ 45963 ] | MariaDB v3 [ 66649 ] |
| Assignee | Igor Babaev [ igor ] |
| Component/s | Optimizer [ 10200 ] | |
| Fix Version/s | 5.3.12 [ 12000 ] | |
| Fix Version/s | 5.3.13 [ 12602 ] | |
| Assignee | Igor Babaev [ igor ] | |
| Resolution | Fixed [ 1 ] | |
| Status | Open [ 1 ] | Closed [ 6 ] |
| Workflow | MariaDB v3 [ 66649 ] | MariaDB v4 [ 146323 ] |
It was fixed in 5.3.12, here is the commit message:
revno: 3612revision-id: igor@askmonty.org-20130112042634-peaxz8hj6e32rqlnparent: wlad@montyprogram.com-20130111114421-j0y44s7tpukn7i9mcommitter: Igor Babaev <igor@askmonty.org>branch nick: maria-5.3timestamp: Fri 2013-01-11 20:26:34 -0800message:Fixed bug mdev-4025.The bug could lead to a wrong estimate of the number of expected rowsin the output of the EXPLAIN commands for queries with GROUP BY.This could be observed in the test case for LP bug 934348.