Query time 0.00043
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "72.01"
},
"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": 10,
"rows_produced_per_join": 10,
"filtered": "100.00",
"index_condition": "((`portal`.`q_discussion`.`object_id` in (12478,12503,12504,12505,12508,12511,12514,12515,12518,12519)) and (`portal`.`q_discussion`.`object_type` = 'P'))",
"cost_info": {
"read_cost": "22.01",
"eval_cost": "2.00",
"prefix_cost": "24.01",
"data_read_per_join": "160"
},
"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": 20,
"filtered": "100.00",
"cost_info": {
"read_cost": "20.00",
"eval_cost": "4.00",
"prefix_cost": "48.01",
"data_read_per_join": "8K"
},
"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": 20,
"filtered": "100.00",
"cost_info": {
"read_cost": "20.00",
"eval_cost": "4.00",
"prefix_cost": "72.01",
"data_read_per_join": "320"
},
"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 |
12478 |
|
B |
26878 |
12503 |
|
B |
17779 |
12504 |
|
B |
17780 |
12505 |
|
B |
17787 |
12508 |
|
B |
17793 |
12511 |
|
B |
17802 |
12514 |
|
B |
17811 |
12515 |
|
B |
17810 |
12518 |
|
B |
17817 |
12519 |
|
B |
17821 |