Details
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Bug
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Status: Open (View Workflow)
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Major
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Resolution: Unresolved
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11.0(EOL)
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None
Description
Check out this example:
create table t1 (a int);
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insert into t1 select seq from seq_1_to_10;
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create table t2 (a int);
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insert into t2 select seq from seq_1_to_10;
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analyze format=json
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select *
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from t1, t2
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where t1.a=t2.a;
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Shows
...
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{
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"block-nl-join": { |
"table": { |
"table_name": "t2", |
"access_type": "all", |
"loops": 10, |
"r_loops": 1, |
"rows": 10, |
"r_rows": 10, |
"cost": 0.02238006, |
"r_table_time_ms": 0.060573394, |
"r_other_time_ms": 0.00925612, |
"filtered": 100, |
"r_filtered": 100 |
},
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"buffer_type": "flat", |
"buffer_size": "65", |
"join_type": "BNL", |
"attached_condition": "t2.a = t1.a", |
"r_filtered": 10, |
"r_unpack_time_ms": 0.004839758 |
}
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This part looks very misleading:
"table": {
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"table_name": "t2",
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"access_type": "all",
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"loops": 10,
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"r_loops": 1,
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We do not expect table t2 to be read 10 times.
"loops" should outside of table object, in block-nl-join.