Query time 0.00059
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 (29301,29302,29303,29304,29305,29306,29307,29308,29309,29310,29311,29312,29313,29314,29315,29316,29317,29318,29319,29320,29321,29322,29323,29324,29325,29326,29327,29328,29329,29330,29331,29332)) 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 |
29301 |
|
B |
20174 |
29302 |
|
B |
20171 |
29303 |
|
B |
20168 |
29304 |
|
B |
20167 |
29305 |
|
B |
20165 |
29306 |
|
B |
20163 |
29307 |
|
B |
20161 |
29308 |
|
B |
20160 |
29309 |
|
B |
20158 |
29310 |
|
B |
20157 |
29311 |
|
B |
20156 |
29312 |
|
B |
20335 |
29313 |
|
B |
20333 |
29314 |
|
B |
20331 |
29315 |
|
B |
20327 |
29316 |
|
B |
20326 |
29317 |
|
B |
20324 |
29318 |
|
B |
20322 |
29319 |
|
B |
20320 |
29320 |
|
B |
20318 |
29321 |
|
B |
20316 |
29322 |
|
B |
20314 |
29323 |
|
B |
20312 |
29324 |
|
B |
20423 |
29325 |
|
B |
20310 |
29326 |
|
B |
20308 |
29327 |
|
B |
20305 |
29328 |
|
B |
20304 |
29329 |
|
B |
20131 |
29330 |
|
B |
20130 |
29331 |
|
B |
20129 |
29332 |
|
B |
20126 |