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 (32554,32555,32556,32557,32558,32559,32560,32562,32563,32564,32565,32566,32567,32568,32569,32570,32571,32573,32574,32575,32576,32577,32579,32580,32581,32582,32583,32584,32585,32586,32588,32589)) 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 |
32554 |
|
B |
22170 |
32555 |
|
B |
22169 |
32556 |
|
B |
22163 |
32557 |
|
B |
22164 |
32558 |
|
B |
22165 |
32559 |
|
B |
22162 |
32560 |
|
B |
21672 |
32562 |
|
B |
21671 |
32563 |
|
B |
21670 |
32564 |
|
B |
21664 |
32565 |
|
B |
21663 |
32566 |
|
B |
21662 |
32567 |
|
B |
21661 |
32568 |
|
B |
21660 |
32569 |
|
B |
21659 |
32570 |
|
B |
21658 |
32571 |
|
B |
21657 |
32573 |
|
B |
21656 |
32574 |
|
B |
21655 |
32575 |
|
B |
21654 |
32576 |
|
B |
21653 |
32577 |
|
B |
21651 |
32579 |
|
B |
21650 |
32580 |
|
B |
21649 |
32581 |
|
B |
21647 |
32582 |
|
B |
21546 |
32583 |
|
B |
21547 |
32584 |
|
B |
21549 |
32585 |
|
B |
21452 |
32586 |
|
B |
21453 |
32588 |
|
B |
21454 |
32589 |
|
B |
21456 |