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 (32654,32655,32656,32657,32658,32659,32660,32661,32662,32663,32664,32665,32666,32667,32668,32669,32671,32672,32673,32675,32676,32677,32679,32680,32681,32682,32683,32684,32685,32686,32687,32688)) 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 |
32654 |
|
B |
21399 |
32655 |
|
B |
21381 |
32656 |
|
B |
21397 |
32657 |
|
B |
21394 |
32658 |
|
B |
21379 |
32659 |
|
B |
21462 |
32660 |
|
B |
21465 |
32661 |
|
B |
21466 |
32662 |
|
B |
21468 |
32663 |
|
B |
21469 |
32664 |
|
B |
21471 |
32665 |
|
B |
21472 |
32666 |
|
B |
21474 |
32667 |
|
B |
21477 |
32668 |
|
B |
21478 |
32669 |
|
B |
21480 |
32671 |
|
B |
21481 |
32672 |
|
B |
21482 |
32673 |
|
B |
21483 |
32675 |
|
B |
21484 |
32676 |
|
B |
21485 |
32677 |
|
B |
21487 |
32679 |
|
B |
21488 |
32680 |
|
B |
21444 |
32681 |
|
B |
21490 |
32682 |
|
B |
21493 |
32683 |
|
B |
21550 |
32684 |
|
B |
21544 |
32685 |
|
B |
21543 |
32686 |
|
B |
21541 |
32687 |
|
B |
21540 |
32688 |
|
B |
21538 |