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 (29201,29202,29203,29204,29205,29206,29207,29208,29209,29210,29211,29212,29213,29214,29215,29216,29218,29219,29220,29221,29222,29223,29224,29225,29226,29227,29228,29229,29230,29231,29232,29233)) 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 |
29201 |
|
B |
20056 |
29202 |
|
B |
20054 |
29203 |
|
B |
20052 |
29204 |
|
B |
20048 |
29205 |
|
B |
20047 |
29206 |
|
B |
20044 |
29207 |
|
B |
20123 |
29208 |
|
B |
20043 |
29209 |
|
B |
20041 |
29210 |
|
B |
20040 |
29211 |
|
B |
20039 |
29212 |
|
B |
20034 |
29213 |
|
B |
20033 |
29214 |
|
B |
20031 |
29215 |
|
B |
20029 |
29216 |
|
B |
20027 |
29218 |
|
B |
20024 |
29219 |
|
B |
20022 |
29220 |
|
B |
20020 |
29221 |
|
B |
20019 |
29222 |
|
B |
20015 |
29223 |
|
B |
20014 |
29224 |
|
B |
20012 |
29225 |
|
B |
20010 |
29226 |
|
B |
20008 |
29227 |
|
B |
20007 |
29228 |
|
B |
20121 |
29229 |
|
B |
20006 |
29230 |
|
B |
20005 |
29231 |
|
B |
20004 |
29232 |
|
B |
20003 |
29233 |
|
B |
20001 |