Details
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Bug
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Status: Closed (View Workflow)
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Major
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Resolution: Fixed
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11.5
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None
Description
It is expected that for the table without partitions and the table with partitions with the same data set, the values like "r_total_filtered" and "r_icp_filtered" from "aanalyze format=json select ..." will be the same. But in this case this is not so:
Table without partitions:
create table t1 (a int, b varchar(10), c int, index(a,b)); |
insert into t1(a,b,c) values (1,"abc",100), |
(2,"abd",200),(2,"bfd",300),(2,"efg",400), |
(3,"abc",410),(3,"def",420),(3,"ghi",430),(3,"jkl",440), |
(4,"abc",600),(4,"def",700),(4,"ghi",800),(4,"jkl",900); |
 |
analyze table t1; |
analyze format=json select * from t1 where t1.a=2 and t1.b like '%f%'; |
drop table t1; |
Result:
ANALYZE
|
{
|
"query_optimization": { |
"r_total_time_ms": 0.077098789 |
},
|
"query_block": { |
"select_id": 1, |
"cost": 0.004492149, |
"r_loops": 1, |
"r_total_time_ms": 0.017491363, |
"nested_loop": [ |
{
|
"table": { |
"table_name": "t1", |
"access_type": "ref", |
"possible_keys": ["a"], |
"key": "a", |
"key_length": "5", |
"used_key_parts": ["a"], |
"ref": ["const"], |
"loops": 1, |
"r_loops": 1, |
"rows": 3, |
"r_index_rows": 3, |
"r_rows": 2, |
"cost": 0.004492149, |
"r_table_time_ms": 0.010259051, |
"r_other_time_ms": 0.005597638, |
"r_engine_stats": {}, |
"filtered": 100, |
"r_total_filtered": 66.66666667, |
"index_condition": "t1.b like '%f%'", |
"r_icp_filtered": 66.66666667, |
"r_filtered": 100 |
}
|
}
|
]
|
}
|
}
|
Table with partitions:
create table t1 (a int, b varchar(10), c int, index(a,b)) |
partition by hash(a) partitions 4; |
 |
insert into t1(a,b,c) values (1,"abc",100), |
(2,"abd",200),(2,"bfd",300),(2,"efg",400), |
(3,"abc",410),(3,"def",420),(3,"ghi",430),(3,"jkl",440), |
(4,"abc",600),(4,"def",700),(4,"ghi",800),(4,"jkl",900); |
analyze table t1; |
analyze format=json select * from t1 where t1.a=2 and t1.b like '%f%'; |
drop table t1; |
Result:
ANALYZE
|
{
|
"query_optimization": { |
"r_total_time_ms": 0.100843591 |
},
|
"query_block": { |
"select_id": 1, |
"cost": 0.004492149, |
"r_loops": 1, |
"r_total_time_ms": 0.03108695, |
"nested_loop": [ |
{
|
"table": { |
"table_name": "t1", |
"partitions": ["p2"], |
"access_type": "ref", |
"possible_keys": ["a"], |
"key": "a", |
"key_length": "5", |
"used_key_parts": ["a"], |
"ref": ["const"], |
"loops": 1, |
"r_loops": 1, |
"rows": 3, |
"r_index_rows": 0, |
"r_rows": 2, |
"cost": 0.004492149, |
"r_table_time_ms": 0.01505605, |
"r_other_time_ms": 0.009645094, |
"r_engine_stats": {}, |
"filtered": 100, |
"r_total_filtered": 100, |
"index_condition": "t1.b like '%f%'", |
"r_icp_filtered": 100, |
"r_filtered": 100 |
}
|
}
|
]
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}
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}
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The case was executed on the branch "bb-11.4-MDEV-18478v4MDEV-12404". This branch has changes from MDEV-12404 and MDEV-18478
Attachments
Issue Links
- is caused by
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MDEV-12404 index condition pushdown on partitioned tables
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- Closed
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