Query time 0.00073
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 (8440,8441,8442,8443,8444,8445,8446,8447,8449,8450,8451,8452,8453,8454,8455,8457,8458,8459,8460,8461,8462,8463,8464,8465,8466,8467,8468,8469,8470,8471,8472,8473)) 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 |
8440 |
|
D |
4703 |
8441 |
|
D |
4704 |
8442 |
|
D |
4690 |
8443 |
|
D |
4691 |
8444 |
|
D |
4692 |
8445 |
|
D |
4694 |
8446 |
|
D |
4695 |
8447 |
|
D |
4696 |
8449 |
|
D |
4698 |
8450 |
|
D |
4699 |
8451 |
|
D |
4700 |
8452 |
|
D |
4363 |
8453 |
|
D |
4364 |
8454 |
|
D |
4365 |
8455 |
|
D |
4366 |
8457 |
|
D |
4701 |
8458 |
|
D |
4702 |
8459 |
|
D |
4597 |
8460 |
|
D |
4598 |
8461 |
|
D |
4596 |
8462 |
|
D |
4352 |
8463 |
|
D |
4353 |
8464 |
|
D |
4354 |
8465 |
|
D |
4355 |
8466 |
|
D |
4356 |
8467 |
|
D |
4357 |
8468 |
|
D |
4358 |
8469 |
|
D |
4359 |
8470 |
|
D |
4360 |
8471 |
|
D |
4362 |
8472 |
|
D |
4341 |
8473 |
|
D |
4344 |