Query time 0.00053
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "194.41"
},
"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": 27,
"rows_produced_per_join": 27,
"filtered": "100.00",
"index_condition": "((`portal`.`q_discussion`.`object_id` in (3741,3742,3743,3744,3745,3746,3747,3748,3749,3750,3751,3752,3753,3755,3756,3757,3758,3759,3760,3761,3762,3764,3765,3768,3769,3772,1470)) and (`portal`.`q_discussion`.`object_type` = 'P'))",
"cost_info": {
"read_cost": "59.41",
"eval_cost": "5.40",
"prefix_cost": "64.81",
"data_read_per_join": "432"
},
"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": 54,
"filtered": "100.00",
"cost_info": {
"read_cost": "54.00",
"eval_cost": "10.80",
"prefix_cost": "129.61",
"data_read_per_join": "23K"
},
"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": 54,
"filtered": "100.00",
"cost_info": {
"read_cost": "54.00",
"eval_cost": "10.80",
"prefix_cost": "194.41",
"data_read_per_join": "864"
},
"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 |
1470 |
|
D |
767 |
3742 |
|
D |
2096 |
3743 |
|
D |
2097 |
3744 |
|
D |
2098 |
3745 |
|
D |
2099 |
3746 |
|
B |
28463 |
3747 |
|
D |
2100 |
3748 |
|
D |
2101 |
3749 |
|
D |
2102 |
3750 |
|
D |
2103 |
3751 |
|
D |
2104 |
3752 |
|
D |
2105 |
3753 |
|
D |
2106 |
3755 |
|
D |
2108 |
3756 |
|
D |
2109 |
3757 |
|
D |
2110 |
3758 |
|
D |
2111 |
3759 |
|
D |
2112 |
3760 |
|
D |
2113 |
3761 |
|
D |
2114 |
3762 |
|
D |
2115 |
3764 |
|
D |
2117 |
3768 |
|
D |
2015 |
3769 |
|
D |
2017 |
3772 |
|
D |
2021 |