Query time 0.00078
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "230.41"
},
"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": 32,
"rows_produced_per_join": 32,
"filtered": "100.00",
"index_condition": "((`portal`.`q_discussion`.`object_id` in (32447,32448,32450,32451,32452,32453,32454,32455,32456,32457,32458,32460,32461,32462,32463,32465,32466,32467,32468,32469,32471,32472,32473,32474,32475,32476,32478,32479,32480,32481,32482,32483)) and (`portal`.`q_discussion`.`object_type` = 'P'))",
"cost_info": {
"read_cost": "70.41",
"eval_cost": "6.40",
"prefix_cost": "76.81",
"data_read_per_join": "512"
},
"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": 64,
"filtered": "100.00",
"cost_info": {
"read_cost": "64.00",
"eval_cost": "12.80",
"prefix_cost": "153.61",
"data_read_per_join": "28K"
},
"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": 64,
"filtered": "100.00",
"cost_info": {
"read_cost": "64.00",
"eval_cost": "12.80",
"prefix_cost": "230.41",
"data_read_per_join": "1024"
},
"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 |
32447 |
|
B |
22661 |
32448 |
|
B |
22660 |
32450 |
|
B |
22516 |
32451 |
|
B |
22518 |
32452 |
|
B |
22519 |
32453 |
|
B |
22520 |
32454 |
|
B |
22522 |
32455 |
|
B |
22523 |
32456 |
|
B |
22524 |
32457 |
|
B |
22553 |
32458 |
|
B |
22545 |
32460 |
|
B |
22526 |
32461 |
|
B |
22525 |
32462 |
|
B |
22261 |
32463 |
|
B |
22260 |
32465 |
|
B |
22262 |
32466 |
|
B |
22258 |
32467 |
|
B |
22257 |
32468 |
|
B |
22255 |
32469 |
|
B |
22254 |
32471 |
|
B |
22251 |
32472 |
|
B |
22252 |
32473 |
|
B |
22248 |
32474 |
|
B |
22246 |
32475 |
|
B |
22244 |
32476 |
|
B |
22245 |
32478 |
|
B |
20880 |
32479 |
|
B |
20881 |
32480 |
|
B |
20882 |
32481 |
|
B |
20883 |
32482 |
|
B |
20884 |
32483 |
|
B |
20885 |