Query time 0.00053
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 (34239,34249,34250,34262,34349,34469,34487,34538,2464,2465,2466,2467,2469,1175,1176,1177,1178,1179,1180,1181,1182,1183,1184,1191,1011,1010,1009,999,998,997,975,958)) 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 |
958 |
|
D |
376 |
975 |
|
D |
393 |
997 |
|
D |
415 |
998 |
|
D |
416 |
999 |
|
D |
417 |
1009 |
|
D |
427 |
1010 |
|
D |
428 |
1011 |
|
D |
429 |
1175 |
|
D |
723 |
1176 |
|
D |
722 |
1177 |
|
D |
528 |
1178 |
|
D |
721 |
1179 |
|
D |
720 |
1180 |
|
D |
719 |
1181 |
|
D |
718 |
1182 |
|
D |
717 |
1183 |
|
D |
716 |
1184 |
|
D |
715 |
1191 |
|
D |
756 |
2464 |
|
D |
1011 |
2465 |
|
D |
1012 |
2466 |
|
D |
1013 |
2467 |
|
D |
1014 |
2469 |
|
D |
1016 |