Query time 0.00059
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "187.21"
},
"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": 26,
"rows_produced_per_join": 26,
"filtered": "100.00",
"index_condition": "((`portal`.`q_discussion`.`object_id` in (41339,29354,29395,29396,30848,30922,31133,13615,13626,13652,10455,10456,1519,1520,1521,1524,1525,1526,1527,1143,1142,1141,1140,1139,1138,1137)) and (`portal`.`q_discussion`.`object_type` = 'P'))",
"cost_info": {
"read_cost": "57.21",
"eval_cost": "5.20",
"prefix_cost": "62.41",
"data_read_per_join": "416"
},
"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": 52,
"filtered": "100.00",
"cost_info": {
"read_cost": "52.00",
"eval_cost": "10.40",
"prefix_cost": "124.81",
"data_read_per_join": "22K"
},
"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": 52,
"filtered": "100.00",
"cost_info": {
"read_cost": "52.00",
"eval_cost": "10.40",
"prefix_cost": "187.21",
"data_read_per_join": "832"
},
"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 |
1137 |
|
D |
492 |
1138 |
|
D |
493 |
1139 |
|
D |
494 |
1140 |
|
D |
495 |
1141 |
|
D |
496 |
1142 |
|
D |
497 |
1143 |
|
D |
498 |
1519 |
|
D |
935 |
1521 |
|
D |
906 |
1524 |
|
D |
909 |
1525 |
|
D |
913 |
1526 |
|
D |
914 |
1527 |
|
D |
915 |
10455 |
|
B |
6678 |
10456 |
|
B |
6679 |
13615 |
|
B |
13042 |
13626 |
|
B |
13061 |
13652 |
|
B |
13133 |
29354 |
|
B |
20269 |
29395 |
|
B |
20373 |
29396 |
|
B |
20371 |
30848 |
|
B |
22636 |
30922 |
|
B |
22698 |
31133 |
|
B |
23461 |