Query time 0.00049
JSON explain
{
"query_block": {
"select_id": 1,
"cost_info": {
"query_cost": "1.56"
},
"grouping_operation": {
"using_temporary_table": true,
"using_filesort": true,
"nested_loop": [
{
"table": {
"table_name": "cscart_product_reviews",
"access_type": "ref",
"possible_keys": [
"PRIMARY",
"idx_product_id"
],
"key": "idx_product_id",
"used_key_parts": [
"product_id"
],
"key_length": "3",
"ref": [
"const"
],
"rows_examined_per_scan": 1,
"rows_produced_per_join": 0,
"filtered": "10.00",
"index_condition": "(`webmarco`.`cscart_product_reviews`.`product_id` <=> 388623)",
"cost_info": {
"read_cost": "1.00",
"eval_cost": "0.02",
"prefix_cost": "1.20",
"data_read_per_join": "167"
},
"used_columns": [
"product_review_id",
"product_id",
"country_code",
"reply_user_id",
"status"
],
"attached_condition": "(`webmarco`.`cscart_product_reviews`.`status` = 'A')"
}
},
{
"table": {
"table_name": "cscart_users",
"access_type": "eq_ref",
"possible_keys": [
"PRIMARY"
],
"key": "PRIMARY",
"used_key_parts": [
"user_id"
],
"key_length": "3",
"ref": [
"webmarco.cscart_product_reviews.reply_user_id"
],
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"filtered": "100.00",
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"read_cost": "0.10",
"eval_cost": "0.02",
"prefix_cost": "1.32",
"data_read_per_join": "659"
},
"used_columns": [
"user_id",
"company_id"
]
}
},
{
"table": {
"table_name": "cscart_companies",
"access_type": "eq_ref",
"possible_keys": [
"PRIMARY"
],
"key": "PRIMARY",
"used_key_parts": [
"company_id"
],
"key_length": "4",
"ref": [
"webmarco.cscart_users.company_id"
],
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"read_cost": "0.10",
"eval_cost": "0.02",
"prefix_cost": "1.44",
"data_read_per_join": "975"
},
"used_columns": [
"company_id"
]
}
},
{
"table": {
"table_name": "cscart_country_descriptions",
"access_type": "eq_ref",
"possible_keys": [
"PRIMARY"
],
"key": "PRIMARY",
"used_key_parts": [
"code",
"lang_code"
],
"key_length": "12",
"ref": [
"webmarco.cscart_product_reviews.country_code",
"const"
],
"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": "1.56",
"data_read_per_join": "40"
},
"used_columns": [
"code",
"lang_code"
]
}
}
]
}
}
}