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 (32721,32722,32723,32724,32725,32726,32727,32728,32729,32730,32731,32732,32733,32734,32735,32736,32737,32738,32739,32740,32741,32742,32743,32744,32745,32746,32747,32748,32749,32750,32751,32752)) 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 |
32721 |
|
B |
21582 |
32722 |
|
B |
21581 |
32723 |
|
B |
21580 |
32724 |
|
B |
21578 |
32725 |
|
B |
21577 |
32726 |
|
B |
21576 |
32727 |
|
B |
21575 |
32728 |
|
B |
21573 |
32729 |
|
B |
21572 |
32730 |
|
B |
21571 |
32731 |
|
B |
21568 |
32732 |
|
B |
21567 |
32733 |
|
B |
21620 |
32734 |
|
B |
21565 |
32735 |
|
B |
21564 |
32736 |
|
B |
21563 |
32737 |
|
B |
21562 |
32738 |
|
B |
21560 |
32739 |
|
B |
21558 |
32740 |
|
B |
21557 |
32741 |
|
B |
21619 |
32742 |
|
B |
21618 |
32743 |
|
B |
21616 |
32744 |
|
B |
21615 |
32745 |
|
B |
21613 |
32746 |
|
B |
21611 |
32747 |
|
B |
21609 |
32748 |
|
B |
21608 |
32749 |
|
B |
21636 |
32750 |
|
B |
21607 |
32751 |
|
B |
21605 |
32752 |
|
B |
21604 |