Query time 0.00073
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "201.61"
},
"grouping_operation": {
"using_filesort": false,
"nested_loop": [
{
"table": {
"table_name": "q_discussion",
"access_type": "range",
"possible_keys": [
"object_id"
],
"key": "object_id",
"used_key_parts": [
"object_id",
"object_type"
],
"key_length": "6",
"rows_examined_per_scan": 28,
"rows_produced_per_join": 28,
"filtered": "100.00",
"index_condition": "((`portal`.`q_discussion`.`object_id` in (1145,1144,1136,1135,1134,1090,1089,1088,1087,1086,1084,1083,1081,1013,1012,921,761,760,759,758,757,756,739,738,737,736,735,734)) and (`portal`.`q_discussion`.`object_type` = 'P'))",
"cost_info": {
"read_cost": "61.61",
"eval_cost": "5.60",
"prefix_cost": "67.21",
"data_read_per_join": "448"
},
"used_columns": [
"thread_id",
"object_id",
"object_type",
"type"
]
}
},
{
"table": {
"table_name": "q_discussion_posts",
"access_type": "ref",
"possible_keys": [
"thread_id",
"thread_id_2"
],
"key": "thread_id",
"used_key_parts": [
"thread_id"
],
"key_length": "3",
"ref": [
"portal.q_discussion.thread_id"
],
"rows_examined_per_scan": 2,
"rows_produced_per_join": 56,
"filtered": "100.00",
"cost_info": {
"read_cost": "56.00",
"eval_cost": "11.20",
"prefix_cost": "134.41",
"data_read_per_join": "24K"
},
"used_columns": [
"post_id",
"thread_id",
"status"
],
"attached_condition": "<if>(is_not_null_compl(q_discussion_posts), (`portal`.`q_discussion_posts`.`status` = 'A'), true)"
}
},
{
"table": {
"table_name": "q_discussion_rating",
"access_type": "eq_ref",
"possible_keys": [
"PRIMARY",
"thread_id"
],
"key": "PRIMARY",
"used_key_parts": [
"post_id"
],
"key_length": "3",
"ref": [
"portal.q_discussion_posts.post_id"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 56,
"filtered": "100.00",
"cost_info": {
"read_cost": "56.00",
"eval_cost": "11.20",
"prefix_cost": "201.61",
"data_read_per_join": "896"
},
"used_columns": [
"rating_value",
"post_id",
"thread_id"
],
"attached_condition": "<if>(is_not_null_compl(q_discussion_rating), ((`portal`.`q_discussion_rating`.`thread_id` = `portal`.`q_discussion`.`thread_id`) and (`portal`.`q_discussion_rating`.`rating_value` <> 0)), true)"
}
}
]
}
}
}
Result
product_id |
average_rating |
discussion_type |
discussion_thread_id |
734 |
|
D |
152 |
735 |
|
D |
153 |
736 |
|
D |
154 |
737 |
|
D |
155 |
738 |
|
D |
156 |
739 |
|
D |
157 |
756 |
|
D |
174 |
757 |
|
D |
175 |
758 |
|
D |
176 |
759 |
|
D |
177 |
760 |
|
D |
178 |
761 |
|
D |
179 |
921 |
|
D |
339 |
1012 |
|
D |
430 |
1013 |
|
D |
431 |
1081 |
|
D |
479 |
1083 |
|
D |
481 |
1084 |
|
D |
482 |
1086 |
|
D |
484 |
1087 |
|
D |
485 |
1088 |
|
D |
486 |
1089 |
|
D |
487 |
1090 |
|
D |
488 |
1134 |
|
D |
489 |
1135 |
|
D |
490 |
1136 |
|
D |
491 |
1144 |
|
D |
499 |
1145 |
|
D |
500 |