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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10.3.10, 10.3.21, 5.5(EOL), 10.4(EOL)
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None
Description
When one uses
- join buffer on table $T, with BNL-join
- the table $T uses a range access $RA
- There is also a possible ref access on the same index, but $RA uses
more key parts
then the non-index condition $COND on $T is checked after $T is joined with the contents of the join buffer. It should be checked before that.
(Note that Only condition on non-indexed columns is affected. Index Condition Pushdown works - whatever can be pushed to ICP, will be pushed and checked at appropriate place)
create table ten(a int primary key); |
insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); |
create table hundred (a int); |
insert into hundred select A.a + 10*B.a from ten A, ten B; |
|
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create table t12 ( |
kp1 int, |
kp2 int, |
col1 int, |
col2 int, |
key (kp1, kp2) |
);
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|
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insert into t12 |
select
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A.a,
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B.a,
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A.a + 100*B.a,
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A.a + 100*B.a
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from |
hundred A, hundred B;
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analyze table t12; |
explain format=json
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select * |
from ten A, t12 B |
where |
B.kp1=A.a and |
B.kp1 <= 10 and |
B.kp2 <= 10 and |
B.col1 +1 < 33333;
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shows
| {
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"query_block": {
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"select_id": 1,
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"table": {
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"table_name": "A",
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"access_type": "index",
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"possible_keys": ["PRIMARY"],
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"key": "PRIMARY",
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"key_length": "4",
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"used_key_parts": ["a"],
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"rows": 10,
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"filtered": 100,
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"attached_condition": "A.a <= 10",
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"using_index": true
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},
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"block-nl-join": {
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"table": {
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"table_name": "B",
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"access_type": "range",
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"possible_keys": ["kp1"],
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"key": "kp1",
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"key_length": "10",
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"used_key_parts": ["kp1", "kp2"],
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"rows": 1011,
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"filtered": 10.148,
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"index_condition": "B.kp2 <= 10"
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},
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"buffer_type": "flat",
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"buffer_size": "54",
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"join_type": "BNL",
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"attached_condition": "B.kp1 = A.a and B.col1 + 1 < 33333"
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}
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}
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} |
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Note that B.col1 + 1 < 33333 is checked when doing the join with the join buffer.
Attachments
Issue Links
- relates to
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- Closed
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