Query time 0.00067
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "187.21"
},
"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": 26,
"rows_produced_per_join": 26,
"filtered": "100.00",
"index_condition": "((`portal`.`q_discussion`.`object_id` in (10514,10341,10353,10366,10367,10371,10372,10373,10374,10022,10026,10031,10033,10035,10036,10037,10038,10041,10042,10045,10046,10048,10051,8682,8214,4584)) and (`portal`.`q_discussion`.`object_type` = 'P'))",
"cost_info": {
"read_cost": "57.21",
"eval_cost": "5.20",
"prefix_cost": "62.41",
"data_read_per_join": "416"
},
"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": 52,
"filtered": "100.00",
"cost_info": {
"read_cost": "52.00",
"eval_cost": "10.40",
"prefix_cost": "124.81",
"data_read_per_join": "22K"
},
"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": 52,
"filtered": "100.00",
"cost_info": {
"read_cost": "52.00",
"eval_cost": "10.40",
"prefix_cost": "187.21",
"data_read_per_join": "832"
},
"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 |
8214 |
|
D |
4517 |
8682 |
|
D |
4196 |
10022 |
|
D |
4279 |
10026 |
|
D |
4283 |
10031 |
|
D |
4292 |
10033 |
|
D |
4297 |
10035 |
|
D |
4305 |
10036 |
|
D |
4309 |
10037 |
|
D |
4321 |
10038 |
|
D |
4322 |
10041 |
|
D |
4347 |
10042 |
|
D |
4371 |
10045 |
4.5000 |
B |
4381 |
10046 |
|
D |
4374 |
10048 |
|
D |
4370 |
10051 |
|
D |
4367 |
10341 |
|
D |
5184 |
10353 |
|
D |
5278 |
10366 |
|
D |
5340 |
10367 |
|
D |
5379 |
10371 |
|
D |
5382 |
10372 |
|
D |
5401 |
10373 |
|
D |
5383 |
10374 |
|
D |
5392 |
10514 |
|
D |
5580 |