Query time 0.00057
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "216.01"
},
"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": 30,
"rows_produced_per_join": 30,
"filtered": "100.00",
"index_condition": "((`portal`.`q_discussion`.`object_id` in (790,789,788,787,786,785,784,783,782,781,780,779,778,777,776,775,774,773,772,771,770,769,768,767,766,765,764,763,762,761)) and (`portal`.`q_discussion`.`object_type` = 'P'))",
"cost_info": {
"read_cost": "66.01",
"eval_cost": "6.00",
"prefix_cost": "72.01",
"data_read_per_join": "480"
},
"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": 60,
"filtered": "100.00",
"cost_info": {
"read_cost": "60.00",
"eval_cost": "12.00",
"prefix_cost": "144.01",
"data_read_per_join": "26K"
},
"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": 60,
"filtered": "100.00",
"cost_info": {
"read_cost": "60.00",
"eval_cost": "12.00",
"prefix_cost": "216.01",
"data_read_per_join": "960"
},
"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 |
761 |
|
D |
179 |
762 |
|
D |
180 |
763 |
|
D |
181 |
764 |
|
D |
182 |
765 |
|
D |
183 |
766 |
|
D |
184 |
767 |
|
D |
185 |
768 |
|
D |
186 |
769 |
|
D |
187 |
770 |
|
D |
188 |
771 |
|
D |
189 |
772 |
|
D |
190 |
773 |
|
D |
191 |
774 |
|
D |
192 |
775 |
|
D |
193 |
776 |
|
D |
194 |
777 |
|
D |
195 |
778 |
|
D |
196 |
779 |
|
D |
197 |
780 |
|
D |
198 |
781 |
|
D |
199 |
782 |
|
D |
200 |
783 |
|
D |
201 |
784 |
|
D |
202 |
785 |
|
D |
203 |
786 |
|
D |
204 |
787 |
|
D |
205 |
788 |
|
D |
206 |
789 |
|
D |
207 |
790 |
|
D |
208 |