Query time 0.00297
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 (32817,32818,32819,32820,32821,32822,32823,32824,32825,32826,32827,32828,32829,32830,32831,32832,32833,32834,32835,32836,32837,32838,32839,32840,32841,32842,32843,32844,32845,32846,32847,32848)) 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 |
32817 |
|
B |
21287 |
32818 |
|
B |
21289 |
32819 |
|
B |
21290 |
32820 |
|
B |
21292 |
32821 |
|
B |
21293 |
32822 |
|
B |
21295 |
32823 |
|
B |
21297 |
32824 |
|
B |
21298 |
32825 |
|
B |
21299 |
32826 |
|
B |
21301 |
32827 |
|
B |
21728 |
32828 |
|
B |
21726 |
32829 |
|
B |
21719 |
32830 |
|
B |
21303 |
32831 |
|
B |
21305 |
32832 |
|
B |
21307 |
32833 |
|
B |
21308 |
32834 |
|
B |
21309 |
32835 |
|
B |
21311 |
32836 |
|
B |
21313 |
32837 |
|
B |
21314 |
32838 |
|
B |
21315 |
32839 |
|
B |
21316 |
32840 |
|
B |
21317 |
32841 |
|
B |
21319 |
32842 |
|
B |
21320 |
32843 |
|
B |
21321 |
32844 |
|
B |
21322 |
32845 |
|
B |
21325 |
32846 |
|
B |
21326 |
32847 |
|
B |
21327 |
32848 |
|
B |
21718 |