Query time 0.00096
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 (32849,32850,32851,32852,32853,32854,32855,32856,32857,32858,32859,32860,32861,32862,32863,32864,32865,32866,32867,32868,32869,32870,32871,32872,32873,32874,32875,32876,32877,32878,32879,32880)) 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 |
32849 |
|
B |
21084 |
32850 |
|
B |
21086 |
32851 |
|
B |
21087 |
32852 |
|
B |
21089 |
32853 |
|
B |
21090 |
32854 |
|
B |
21092 |
32855 |
|
B |
21094 |
32856 |
|
B |
21096 |
32857 |
|
B |
21100 |
32858 |
|
B |
21103 |
32859 |
|
B |
21104 |
32860 |
|
B |
21110 |
32861 |
|
B |
21113 |
32862 |
|
B |
21114 |
32863 |
|
B |
21115 |
32864 |
|
B |
21116 |
32865 |
|
B |
21117 |
32866 |
|
B |
21118 |
32867 |
|
B |
21119 |
32868 |
|
B |
21125 |
32869 |
|
B |
21126 |
32870 |
|
B |
21128 |
32871 |
|
B |
21129 |
32872 |
|
B |
20879 |
32873 |
|
B |
20878 |
32874 |
|
B |
20877 |
32875 |
|
B |
20876 |
32876 |
|
B |
20875 |
32877 |
|
B |
20874 |
32878 |
|
B |
20873 |
32879 |
|
B |
20872 |
32880 |
|
B |
20871 |