Query time 0.00067
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 (8395,8396,8397,8398,8399,8400,8401,8402,8403,8404,8405,8406,8407,8408,8409,8410,8412,8414,8415,8419,8425,8426,8427,8428,8429,8430,8431,8432,8435,8436,8438,8439)) 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 |
8395 |
|
D |
4314 |
8396 |
|
D |
4316 |
8397 |
|
D |
4317 |
8398 |
|
D |
4318 |
8399 |
|
D |
4665 |
8400 |
|
D |
4666 |
8401 |
|
D |
4668 |
8402 |
|
D |
4670 |
8403 |
|
D |
4671 |
8404 |
|
D |
4672 |
8405 |
|
D |
4673 |
8406 |
|
D |
4674 |
8407 |
|
D |
4675 |
8408 |
|
D |
4676 |
8409 |
|
D |
4677 |
8410 |
|
D |
4678 |
8412 |
|
D |
4679 |
8414 |
|
D |
4680 |
8415 |
|
D |
4681 |
8419 |
|
D |
4122 |
8425 |
|
D |
4721 |
8426 |
|
D |
4720 |
8427 |
|
D |
4719 |
8428 |
|
D |
4718 |
8429 |
|
D |
4717 |
8430 |
|
D |
4716 |
8431 |
|
D |
4715 |
8432 |
|
D |
4714 |
8435 |
|
D |
4709 |
8436 |
|
D |
4708 |
8438 |
|
D |
4706 |
8439 |
|
D |
4705 |