Query time 0.00064
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 (9837,9838,9839,9840,9841,9842,9843,9844,9845,9846,9847,9848,9849,9850,9851,9852,9853,9854,9855,9856,9857,9858,9859,9860,9861,9862,9863,9864,9865,9866,9867,9868)) 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 |
9837 |
|
D |
5511 |
9838 |
|
D |
5495 |
9839 |
|
D |
5494 |
9840 |
|
D |
5493 |
9841 |
|
D |
5492 |
9842 |
|
D |
5491 |
9843 |
|
D |
5488 |
9844 |
|
D |
5483 |
9845 |
|
D |
5472 |
9846 |
|
D |
5466 |
9847 |
|
D |
5462 |
9848 |
|
D |
5459 |
9849 |
|
D |
5450 |
9850 |
|
D |
5447 |
9851 |
|
D |
5446 |
9852 |
|
D |
5445 |
9853 |
|
D |
5444 |
9854 |
|
D |
5443 |
9855 |
|
D |
5442 |
9856 |
|
D |
5437 |
9857 |
|
D |
5436 |
9858 |
|
D |
5435 |
9859 |
|
D |
5434 |
9860 |
|
D |
5432 |
9861 |
|
D |
5427 |
9862 |
|
D |
5422 |
9863 |
|
D |
5411 |
9864 |
|
D |
5409 |
9865 |
|
D |
5405 |
9866 |
|
D |
5404 |
9867 |
|
D |
4916 |
9868 |
|
D |
4917 |