Query time 0.00045
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "7.66"
},
"grouping_operation": {
"using_filesort": false,
"nested_loop": [
{
"table": {
"table_name": "cscart_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": 3,
"rows_produced_per_join": 3,
"filtered": "100.00",
"index_condition": "((`s2cart`.`cscart_discussion`.`object_id` in (276714,276715,276716)) and (`s2cart`.`cscart_discussion`.`object_type` = 'P'))",
"cost_info": {
"read_cost": "1.81",
"eval_cost": "0.30",
"prefix_cost": "2.11",
"data_read_per_join": "72"
},
"used_columns": [
"thread_id",
"object_id",
"object_type",
"type"
]
}
},
{
"table": {
"table_name": "cscart_discussion_posts",
"access_type": "ref",
"possible_keys": [
"thread_id",
"thread_id_2"
],
"key": "thread_id",
"used_key_parts": [
"thread_id"
],
"key_length": "3",
"ref": [
"s2cart.cscart_discussion.thread_id"
],
"rows_examined_per_scan": 3,
"rows_produced_per_join": 9,
"filtered": "100.00",
"cost_info": {
"read_cost": "1.50",
"eval_cost": "0.90",
"prefix_cost": "4.51",
"data_read_per_join": "3K"
},
"used_columns": [
"post_id",
"thread_id",
"status"
],
"attached_condition": "<if>(is_not_null_compl(cscart_discussion_posts), (`s2cart`.`cscart_discussion_posts`.`status` = 'A'), true)"
}
},
{
"table": {
"table_name": "cscart_discussion_rating",
"access_type": "eq_ref",
"possible_keys": [
"PRIMARY",
"thread_id"
],
"key": "PRIMARY",
"used_key_parts": [
"post_id"
],
"key_length": "3",
"ref": [
"s2cart.cscart_discussion_posts.post_id"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 9,
"filtered": "100.00",
"cost_info": {
"read_cost": "2.25",
"eval_cost": "0.90",
"prefix_cost": "7.66",
"data_read_per_join": "144"
},
"used_columns": [
"rating_value",
"post_id",
"thread_id"
],
"attached_condition": "<if>(is_not_null_compl(cscart_discussion_rating), ((`s2cart`.`cscart_discussion_rating`.`thread_id` = `s2cart`.`cscart_discussion`.`thread_id`) and (`s2cart`.`cscart_discussion_rating`.`rating_value` <> 0)), true)"
}
}
]
}
}
}
Result
product_id |
average_rating |
discussion_type |
discussion_thread_id |
276714 |
|
D |
5977 |
276715 |
|
D |
5978 |
276716 |
|
D |
5979 |