Query time 0.00132
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "1.54"
},
"grouping_operation": {
"using_temporary_table": true,
"using_filesort": true,
"cost_info": {
"sort_cost": "0.10"
},
"nested_loop": [
{
"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": [
"const"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 0,
"filtered": "10.00",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.02",
"prefix_cost": "1.20",
"data_read_per_join": "44"
},
"used_columns": [
"post_id",
"thread_id",
"status"
],
"attached_condition": "(`eshopuga_upgr_4122`.`cscart_discussion_posts`.`status` = 'A')"
}
},
{
"table": {
"table_name": "cscart_discussion_messages",
"access_type": "eq_ref",
"possible_keys": [
"PRIMARY"
],
"key": "PRIMARY",
"used_key_parts": [
"post_id"
],
"key_length": "3",
"ref": [
"eshopuga_upgr_4122.cscart_discussion_posts.post_id"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 0,
"filtered": "100.00",
"using_index": true,
"cost_info": {
"read_cost": "0.10",
"eval_cost": "0.02",
"prefix_cost": "1.32",
"data_read_per_join": "2"
},
"used_columns": [
"post_id"
]
}
},
{
"table": {
"table_name": "cscart_discussion_rating",
"access_type": "eq_ref",
"possible_keys": [
"PRIMARY"
],
"key": "PRIMARY",
"used_key_parts": [
"post_id"
],
"key_length": "3",
"ref": [
"eshopuga_upgr_4122.cscart_discussion_posts.post_id"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 0,
"filtered": "100.00",
"cost_info": {
"read_cost": "0.10",
"eval_cost": "0.02",
"prefix_cost": "1.44",
"data_read_per_join": "1"
},
"used_columns": [
"rating_value",
"post_id"
]
}
}
]
}
}
}