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MDEV-6111: Optimizer Trace: add tracing for semi-join optimizations 

Added:
- "semijoin_strategy_choice" element (actions in advance_sj_state(), name
  matches the name in MySQL)

- semijoin_table_pullout element.
pull/1380/head
Sergei Petrunia 6 years ago
parent
9fce942878
commit
4a490d1a99
3 changed files with 365 additions and 27 deletions
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  1. 273
      mysql-test/main/opt_trace.result
  2. 18
      mysql-test/main/opt_trace.test
  3. 101
      sql/opt_subselect.cc

273
mysql-test/main/opt_trace.result
View File

@ -2662,6 +2662,11 @@ explain extended select * from t1 where a in (select pk from t10) {
}
]
},
{
"semijoin_table_pullout": {
"pulled_out_tables": []
}
},
{
"execution_plan_for_potential_materialization": {
"steps": [
@ -2705,6 +2710,7 @@ explain extended select * from t1 where a in (select pk from t10) {
},
"rows_for_plan": 3,
"cost_for_plan": 2.6066,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t1"],
@ -2720,7 +2726,27 @@ explain extended select * from t1 where a in (select pk from t10) {
]
},
"rows_for_plan": 30,
"cost_for_plan": 10.629
"cost_for_plan": 10.629,
"semijoin_strategy_choice": [
{
"strategy": "FirstMatch",
"records": 3,
"read_time": 10.629
},
{
"strategy": "SJ-Materialization",
"records": 3,
"read_time": 5.2786
},
{
"strategy": "DuplicateWeedout",
"records": 3,
"read_time": 27.129
},
{
"chosen_strategy": "SJ-Materialize"
}
]
}
]
},
@ -2739,6 +2765,7 @@ explain extended select * from t1 where a in (select pk from t10) {
},
"rows_for_plan": 10,
"cost_for_plan": 4.022,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -2746,7 +2773,7 @@ explain extended select * from t1 where a in (select pk from t10) {
{
"fix_semijoin_strategies_for_picked_join_order": [
{
"semi_join_strategy": "sj_materialize",
"semi_join_strategy": "SJ-Materialization",
"join_order": [
{
"table": "t10"
@ -4081,6 +4108,11 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
}
]
},
{
"semijoin_table_pullout": {
"pulled_out_tables": []
}
},
{
"execution_plan_for_potential_materialization": {
"steps": [
@ -4159,6 +4191,7 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t1"],
@ -4175,6 +4208,7 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
},
"rows_for_plan": 9,
"cost_for_plan": 6.4103,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t1", "t_inner_1"],
@ -4190,7 +4224,27 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
]
},
"rows_for_plan": 27,
"cost_for_plan": 13.815
"cost_for_plan": 13.815,
"semijoin_strategy_choice": [
{
"strategy": "FirstMatch",
"records": 3,
"read_time": 26.667
},
{
"strategy": "SJ-Materialization",
"records": 3,
"read_time": 7.2154
},
{
"strategy": "DuplicateWeedout",
"records": 3,
"read_time": 18.315
},
{
"chosen_strategy": "SJ-Materialize"
}
]
}
]
},
@ -4209,6 +4263,7 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
},
"rows_for_plan": 9,
"cost_for_plan": 6.4103,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -4228,6 +4283,7 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -4245,6 +4301,7 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -4252,7 +4309,7 @@ explain select * from t1 where a in (select t_inner_1.a from t1 t_inner_1, t1 t_
{
"fix_semijoin_strategies_for_picked_join_order": [
{
"semi_join_strategy": "sj_materialize",
"semi_join_strategy": "SJ-Materialization",
"join_order": [
{
"table": "t_inner_1"
@ -4511,6 +4568,16 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
}
]
},
{
"semijoin_table_pullout": {
"pulled_out_tables": []
}
},
{
"semijoin_table_pullout": {
"pulled_out_tables": []
}
},
{
"execution_plan_for_potential_materialization": {
"steps": []
@ -4533,6 +4600,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1"],
@ -4549,6 +4617,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 6.4103,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1", "t_inner_1"],
@ -4565,6 +4634,21 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 24.626,
"semijoin_strategy_choice": [
{
"strategy": "FirstMatch",
"records": 3,
"read_time": 26.759
},
{
"strategy": "DuplicateWeedout",
"records": 3,
"read_time": 37.226
},
{
"chosen_strategy": "FirstMatch"
}
],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1", "t_inner_1", "t_inner_2"],
@ -4581,6 +4665,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 34.174,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -4602,6 +4687,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 52.379,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -4623,7 +4709,22 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
]
},
"rows_for_plan": 729,
"cost_for_plan": 200.19
"cost_for_plan": 200.19,
"semijoin_strategy_choice": [
{
"strategy": "FirstMatch",
"records": 27,
"read_time": 251.56
},
{
"strategy": "DuplicateWeedout",
"records": 27,
"read_time": 313.59
},
{
"chosen_strategy": "FirstMatch"
}
]
}
]
},
@ -4647,6 +4748,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 243,
"cost_for_plan": 84.79,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -4666,6 +4768,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 30.564,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -4687,6 +4790,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 48.779,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -4709,6 +4813,16 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 729,
"cost_for_plan": 196.59,
"semijoin_strategy_choice": [
{
"strategy": "DuplicateWeedout",
"records": 27,
"read_time": 309.99
},
{
"chosen_strategy": "DuplicateWeedout"
}
],
"pruned_by_cost": true
}
]
@ -4733,6 +4847,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 48.779,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -4752,6 +4867,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 34.174,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -4771,6 +4887,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 24.626,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1", "t_inner_1", "t_outer_2"],
@ -4787,6 +4904,16 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 729,
"cost_for_plan": 172.44,
"semijoin_strategy_choice": [
{
"strategy": "DuplicateWeedout",
"records": 27,
"read_time": 285.84
},
{
"chosen_strategy": "DuplicateWeedout"
}
],
"pruned_by_cost": true
},
{
@ -4804,6 +4931,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 243,
"cost_for_plan": 75.231,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -4825,6 +4953,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 2187,
"cost_for_plan": 514.65,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
},
{
@ -4847,6 +4976,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 2187,
"cost_for_plan": 514.65,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
}
]
@ -4866,6 +4996,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 729,
"cost_for_plan": 172.44,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -4885,6 +5016,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 13.815,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1", "t_inner_1", "t_inner_4"],
@ -4901,6 +5033,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 243,
"cost_for_plan": 64.431,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -4922,6 +5055,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 2187,
"cost_for_plan": 503.85,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
},
{
@ -4944,6 +5078,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 2187,
"cost_for_plan": 503.85,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
}
]
@ -4963,6 +5098,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 243,
"cost_for_plan": 64.431,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -4980,6 +5116,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 243,
"cost_for_plan": 64.431,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -4999,6 +5136,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 24.626,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1", "t_inner_1", "t_inner_3"],
@ -5015,6 +5153,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 729,
"cost_for_plan": 172.44,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -5036,6 +5175,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 2187,
"cost_for_plan": 611.85,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
},
{
@ -5058,6 +5198,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 6561,
"cost_for_plan": 1486.7,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
}
]
@ -5077,6 +5218,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 243,
"cost_for_plan": 75.231,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -5098,6 +5240,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 2187,
"cost_for_plan": 514.65,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
},
{
@ -5120,6 +5263,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 2187,
"cost_for_plan": 514.65,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
}
]
@ -5139,6 +5283,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 729,
"cost_for_plan": 172.44,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -5160,6 +5305,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 10.021,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -5177,6 +5323,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 10.021,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -5194,6 +5341,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 6.4103,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -5211,6 +5359,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 10.021,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -5230,6 +5379,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -5247,6 +5397,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 3.8154,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -5264,6 +5415,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 3.8154,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -5281,6 +5433,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -5298,6 +5451,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 3.8154,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -5305,7 +5459,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
{
"fix_semijoin_strategies_for_picked_join_order": [
{
"semi_join_strategy": "firstmatch",
"semi_join_strategy": "FirstMatch",
"join_order": [
{
"table": "t_inner_4"
@ -5336,7 +5490,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
]
},
{
"semi_join_strategy": "firstmatch",
"semi_join_strategy": "FirstMatch",
"join_order": [
{
"table": "t_inner_1"
@ -5621,6 +5775,16 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
}
]
},
{
"semijoin_table_pullout": {
"pulled_out_tables": []
}
},
{
"semijoin_table_pullout": {
"pulled_out_tables": []
}
},
{
"execution_plan_for_potential_materialization": {
"steps": [
@ -5754,6 +5918,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1"],
@ -5770,6 +5935,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 6.4103,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1", "t_inner_1"],
@ -5786,6 +5952,26 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 24.626,
"semijoin_strategy_choice": [
{
"strategy": "FirstMatch",
"records": 3,
"read_time": 26.759
},
{
"strategy": "SJ-Materialization",
"records": 3,
"read_time": 8.1256
},
{
"strategy": "DuplicateWeedout",
"records": 3,
"read_time": 37.226
},
{
"chosen_strategy": "SJ-Materialize"
}
],
"rest_of_plan": [
{
"plan_prefix": ["t_outer_1", "t_inner_1", "t_inner_2"],
@ -5802,6 +5988,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 15.541,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -5823,6 +6010,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 33.746,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -5844,7 +6032,27 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
]
},
"rows_for_plan": 729,
"cost_for_plan": 181.56
"cost_for_plan": 181.56,
"semijoin_strategy_choice": [
{
"strategy": "FirstMatch",
"records": 27,
"read_time": 232.93
},
{
"strategy": "SJ-Materialization",
"records": 27,
"read_time": 22.262
},
{
"strategy": "DuplicateWeedout",
"records": 27,
"read_time": 294.96
},
{
"chosen_strategy": "SJ-Materialize"
}
]
}
]
},
@ -5868,6 +6076,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 243,
"cost_for_plan": 66.156,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
}
]
@ -5887,6 +6096,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 11.931,
"semijoin_strategy_choice": [],
"rest_of_plan": [
{
"plan_prefix": [
@ -5908,6 +6118,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 30.146,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
},
{
@ -5930,6 +6141,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 30.146,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
}
]
@ -5949,6 +6161,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 15.541,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -5968,6 +6181,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 24.626,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
},
{
@ -5985,6 +6199,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 13.815,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -6002,6 +6217,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 81,
"cost_for_plan": 24.626,
"semijoin_strategy_choice": [],
"pruned_by_cost": true
}
]
@ -6021,6 +6237,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 10.021,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -6038,6 +6255,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 10.021,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -6055,6 +6273,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 6.4103,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -6072,6 +6291,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 27,
"cost_for_plan": 10.021,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -6091,6 +6311,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -6108,6 +6329,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 3.8154,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -6125,6 +6347,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 3.8154,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -6142,6 +6365,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 3,
"cost_for_plan": 2.6051,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
},
{
@ -6159,6 +6383,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
},
"rows_for_plan": 9,
"cost_for_plan": 3.8154,
"semijoin_strategy_choice": [],
"pruned_by_heuristic": true
}
]
@ -6166,7 +6391,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
{
"fix_semijoin_strategies_for_picked_join_order": [
{
"semi_join_strategy": "sj_materialize",
"semi_join_strategy": "SJ-Materialization",
"join_order": [
{
"table": "t_inner_4"
@ -6177,7 +6402,7 @@ t_outer_2.a in (select t_inner_3.a from t2 t_inner_3, t1 t_inner_4) {
]
},
{
"semi_join_strategy": "sj_materialize",
"semi_join_strategy": "SJ-Materialization",
"join_order": [
{
"table": "t_inner_1"
@ -7026,4 +7251,32 @@ JSON_DETAILED(JSON_EXTRACT(trace, '$**.analyzing_range_alternatives'))
}
]
DROP TABLE t1;
#
# Test for Semi-Join table pullout element
#
create table t1 (a int primary key, b int);
insert into t1 (a) values (1),(2),(3),(4),(5);
create table t2 (a int primary key, b int);
insert into t2 (a) values (1),(2),(3),(4),(5);
create table t3 (a int);
insert into t3 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10);
explain
select * from t3 where (a,a) in (select t1.a, t2.a from t1, t2 where t1.b=t2.b);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 ALL PRIMARY NULL NULL NULL 5
1 PRIMARY t2 eq_ref PRIMARY PRIMARY 4 test.t1.a 1 Using where
1 PRIMARY t3 ALL NULL NULL NULL NULL 10 Using where; Using join buffer (flat, BNL join)
select JSON_DETAILED(JSON_EXTRACT(trace, '$**.semijoin_table_pullout')) from INFORMATION_SCHEMA.OPTIMIZER_TRACE;
JSON_DETAILED(JSON_EXTRACT(trace, '$**.semijoin_table_pullout'))
[
{
"pulled_out_tables":
[
"t2",
"t1"
]
}
]
drop table t1,t2,t3;
set optimizer_trace='enabled=off';

18
mysql-test/main/opt_trace.test
View File

@ -549,4 +549,22 @@ select JSON_DETAILED(JSON_EXTRACT(trace, '$**.analyzing_range_alternatives')) fr
DROP TABLE t1;
--echo #
--echo # Test for Semi-Join table pullout element
--echo #
create table t1 (a int primary key, b int);
insert into t1 (a) values (1),(2),(3),(4),(5);
create table t2 (a int primary key, b int);
insert into t2 (a) values (1),(2),(3),(4),(5);
create table t3 (a int);
insert into t3 values (1),(2),(3),(4),(5),(6),(7),(8),(9),(10);
explain
select * from t3 where (a,a) in (select t1.a, t2.a from t1, t2 where t1.b=t2.b);
select JSON_DETAILED(JSON_EXTRACT(trace, '$**.semijoin_table_pullout')) from INFORMATION_SCHEMA.OPTIMIZER_TRACE;
drop table t1,t2,t3;
set optimizer_trace='enabled=off';

101
sql/opt_subselect.cc
View File

@ -2192,12 +2192,15 @@ int pull_out_semijoin_tables(JOIN *join)
TABLE_LIST *sj_nest;
DBUG_ENTER("pull_out_semijoin_tables");
List_iterator<TABLE_LIST> sj_list_it(join->select_lex->sj_nests);
/* Try pulling out of the each of the semi-joins */
while ((sj_nest= sj_list_it++))
{
List_iterator<TABLE_LIST> child_li(sj_nest->nested_join->join_list);
TABLE_LIST *tbl;
Json_writer_object trace_wrapper(join->thd);
Json_writer_object trace(join->thd, "semijoin_table_pullout");
Json_writer_array trace_arr(join->thd, "pulled_out_tables");
/*
Don't do table pull-out for nested joins (if we get nested joins here, it
@ -2296,7 +2299,8 @@ int pull_out_semijoin_tables(JOIN *join)
pulled_a_table= TRUE;
pulled_tables |= tbl->table->map;
DBUG_PRINT("info", ("Table %s pulled out (reason: func dep)",
tbl->table->alias.c_ptr()));
tbl->table->alias.c_ptr_safe()));
trace_arr.add(tbl->table->alias.c_ptr_safe());
/*
Pulling a table out of uncorrelated subquery in general makes
makes it correlated. See the NOTE to this funtion.
@ -2778,27 +2782,30 @@ void advance_sj_state(JOIN *join, table_map remaining_tables, uint idx,
{
POSITION *pos= join->positions + idx;
const JOIN_TAB *new_join_tab= pos->table;
Semi_join_strategy_picker *pickers[]=
{
&pos->firstmatch_picker,
&pos->loosescan_picker,
&pos->sjmat_picker,
&pos->dups_weedout_picker,
NULL,
};
if (join->emb_sjm_nest)
if (join->emb_sjm_nest || //(1)
!join->select_lex->have_merged_subqueries) //(2)
{
/*
We're performing optimization inside SJ-Materialization nest:
(1): We're performing optimization inside SJ-Materialization nest:
- there are no other semi-joins inside semi-join nests
- attempts to build semi-join strategies here will confuse
the optimizer, so bail out.
(2): Don't waste time on semi-join optimizations if we don't have any
semi-joins
*/
pos->sj_strategy= SJ_OPT_NONE;
return;
}
Semi_join_strategy_picker *pickers[]=
{
&pos->firstmatch_picker,
&pos->loosescan_picker,
&pos->sjmat_picker,
&pos->dups_weedout_picker,
NULL,
};
Json_writer_array trace_steps(join->thd, "semijoin_strategy_choice");
/*
Update join->cur_sj_inner_tables (Used by FirstMatch in this function and
LooseScan detector in best_access_path)
@ -2897,6 +2904,7 @@ void advance_sj_state(JOIN *join, table_map remaining_tables, uint idx,
*current_read_time= read_time;
*current_record_count= rec_count;
dups_producing_tables &= ~handled_fanout;
//TODO: update bitmap of semi-joins that were handled together with
// others.
if (is_multiple_semi_joins(join, join->positions, idx,
@ -2924,6 +2932,30 @@ void advance_sj_state(JOIN *join, table_map remaining_tables, uint idx,
}
}
}
if (unlikely(join->thd->trace_started() && pos->sj_strategy != SJ_OPT_NONE))
{
Json_writer_object tr(join->thd);
const char *sname;
switch (pos->sj_strategy) {
case SJ_OPT_MATERIALIZE:
sname= "SJ-Materialize";
break;
case SJ_OPT_MATERIALIZE_SCAN:
sname= "SJ-Materialize-Scan";
break;
case SJ_OPT_FIRST_MATCH:
sname= "FirstMatch";
break;
case SJ_OPT_DUPS_WEEDOUT:
sname= "DuplicateWeedout";
break;
default:
DBUG_ASSERT(0);
sname="Invalid";
}
tr.add("chosen_strategy", sname);
}
}
if ((emb_sj_nest= new_join_tab->emb_sj_nest))
@ -3000,6 +3032,8 @@ bool Sj_materialization_picker::check_qep(JOIN *join,
}
else
{
Json_writer_object trace(join->thd);
trace.add("strategy", "SJ-Materialization");
/* This is SJ-Materialization with lookups */
Cost_estimate prefix_cost;
signed int first_tab= (int)idx - mat_info->tables;
@ -3032,6 +3066,11 @@ bool Sj_materialization_picker::check_qep(JOIN *join,
*record_count= prefix_rec_count;
*handled_fanout= new_join_tab->emb_sj_nest->sj_inner_tables;
*strategy= SJ_OPT_MATERIALIZE;
if (unlikely(join->thd->trace_started()))
{
trace.add("records", *record_count);
trace.add("read_time", *read_time);
}
return TRUE;
}
}
@ -3040,6 +3079,8 @@ bool Sj_materialization_picker::check_qep(JOIN *join,
if (sjm_scan_need_tables && /* Have SJM-Scan prefix */
!(sjm_scan_need_tables & remaining_tables))
{
Json_writer_object trace(join->thd);
trace.add("strategy", "SJ-Materialization-Scan");
TABLE_LIST *mat_nest=
join->positions[sjm_scan_last_inner].table->emb_sj_nest;
SJ_MATERIALIZATION_INFO *mat_info= mat_nest->sj_mat_info;
@ -3088,6 +3129,11 @@ bool Sj_materialization_picker::check_qep(JOIN *join,
*read_time= prefix_cost;
*record_count= prefix_rec_count;
*handled_fanout= mat_nest->sj_inner_tables;
if (unlikely(join->thd->trace_started()))
{
trace.add("records", *record_count);
trace.add("read_time", *read_time);
}
return TRUE;
}
return FALSE;
@ -3151,6 +3197,8 @@ bool LooseScan_picker::check_qep(JOIN *join,
!(remaining_tables & loosescan_need_tables) &&
(new_join_tab->table->map & loosescan_need_tables))
{
Json_writer_object trace(join->thd);
trace.add("strategy", "SJ-Materialization-Scan");
/*
Ok we have LooseScan plan and also have all LooseScan sj-nest's
inner tables and outer correlated tables into the prefix.
@ -3181,6 +3229,11 @@ bool LooseScan_picker::check_qep(JOIN *join,
*/
*strategy= SJ_OPT_LOOSE_SCAN;
*handled_fanout= first->table->emb_sj_nest->sj_inner_tables;
if (unlikely(join->thd->trace_started()))
{
trace.add("records", *record_count);
trace.add("read_time", *read_time);
}
return TRUE;
}
return FALSE;
@ -3260,6 +3313,8 @@ bool Firstmatch_picker::check_qep(JOIN *join,
if (in_firstmatch_prefix() &&
!(firstmatch_need_tables & remaining_tables))
{
Json_writer_object trace(join->thd);
trace.add("strategy", "FirstMatch");
/*
Got a complete FirstMatch range. Calculate correct costs and fanout
*/
@ -3292,6 +3347,11 @@ bool Firstmatch_picker::check_qep(JOIN *join,
*handled_fanout= firstmatch_need_tables;
/* *record_count and *read_time were set by the above call */
*strategy= SJ_OPT_FIRST_MATCH;
if (unlikely(join->thd->trace_started()))
{
trace.add("records", *record_count);
trace.add("read_time", *read_time);
}
return TRUE;
}
}
@ -3370,6 +3430,8 @@ bool Duplicate_weedout_picker::check_qep(JOIN *join,
double sj_inner_fanout= 1.0;
double sj_outer_fanout= 1.0;
uint temptable_rec_size;
Json_writer_object trace(join->thd);
trace.add("strategy", "DuplicateWeedout");
if (first_tab == join->const_tables)
{
prefix_rec_count= 1.0;
@ -3430,6 +3492,11 @@ bool Duplicate_weedout_picker::check_qep(JOIN *join,
*record_count= prefix_rec_count * sj_outer_fanout;
*handled_fanout= dups_removed_fanout;
*strategy= SJ_OPT_DUPS_WEEDOUT;
if (unlikely(join->thd->trace_started()))
{
trace.add("records", *record_count);
trace.add("read_time", *read_time);
}
return TRUE;
}
return FALSE;
@ -3660,7 +3727,7 @@ void fix_semijoin_strategies_for_picked_join_order(JOIN *join)
join->best_positions[first].n_sj_tables= sjm->tables;
join->best_positions[first].sj_strategy= SJ_OPT_MATERIALIZE;
Json_writer_object semijoin_strategy(thd);
semijoin_strategy.add("semi_join_strategy","sj_materialize");
semijoin_strategy.add("semi_join_strategy","SJ-Materialization");
Json_writer_array semijoin_plan(thd, "join_order");
for (uint i= first; i < first+ sjm->tables; i++)
{
@ -3709,7 +3776,7 @@ void fix_semijoin_strategies_for_picked_join_order(JOIN *join)
POSITION dummy;
join->cur_sj_inner_tables= 0;
Json_writer_object semijoin_strategy(thd);
semijoin_strategy.add("semi_join_strategy","sj_materialize_scan");
semijoin_strategy.add("semi_join_strategy","SJ-Materialization-Scan");
Json_writer_array semijoin_plan(thd, "join_order");
for (i= first + sjm->tables; i <= tablenr; i++)
{
@ -3747,7 +3814,7 @@ void fix_semijoin_strategies_for_picked_join_order(JOIN *join)
*/
join->cur_sj_inner_tables= 0;
Json_writer_object semijoin_strategy(thd);
semijoin_strategy.add("semi_join_strategy","firstmatch");
semijoin_strategy.add("semi_join_strategy","FirstMatch");
Json_writer_array semijoin_plan(thd, "join_order");
for (idx= first; idx <= tablenr; idx++)
{
@ -3785,7 +3852,7 @@ void fix_semijoin_strategies_for_picked_join_order(JOIN *join)
*/
join->cur_sj_inner_tables= 0;
Json_writer_object semijoin_strategy(thd);
semijoin_strategy.add("semi_join_strategy","sj_materialize");
semijoin_strategy.add("semi_join_strategy","LooseScan");
Json_writer_array semijoin_plan(thd, "join_order");
for (idx= first; idx <= tablenr; idx++)
{

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