Query time 0.00054
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "2.90"
},
"ordering_operation": {
"using_filesort": true,
"cost_info": {
"sort_cost": "1.00"
},
"nested_loop": [
{
"table": {
"table_name": "cscart_product_questions",
"access_type": "ALL",
"rows_examined_per_scan": 10,
"rows_produced_per_join": 1,
"filtered": "10.00",
"cost_info": {
"read_cost": "1.45",
"eval_cost": "0.10",
"prefix_cost": "1.55",
"data_read_per_join": "32"
},
"used_columns": [
"question_id",
"timestamp",
"user_id",
"product_id",
"question_text"
],
"attached_condition": "(`cscartdb`.`cscart_product_questions`.`product_id` = 8709)"
}
},
{
"table": {
"table_name": "cscart_profile_fields_data",
"access_type": "eq_ref",
"possible_keys": [
"PRIMARY"
],
"key": "PRIMARY",
"used_key_parts": [
"object_id",
"object_type",
"field_id"
],
"key_length": "9",
"ref": [
"cscartdb.cscart_product_questions.user_id",
"const",
"const"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 1,
"filtered": "100.00",
"index_condition": "(`cscartdb`.`cscart_product_questions`.`user_id` = `cscartdb`.`cscart_profile_fields_data`.`object_id`)",
"cost_info": {
"read_cost": "0.25",
"eval_cost": "0.10",
"prefix_cost": "1.90",
"data_read_per_join": "784"
},
"used_columns": [
"object_id",
"object_type",
"field_id",
"value"
]
}
}
]
}
}
}