查看“︁MySQL explain”︁的源代码

= 例子 =
<pre>
mysql> explain SELECT COUNT(*) FROM vehicle_prod WHERE fin LIKE '%00000' \G
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: vehicle_prod
   partitions: NULL
         type: index
possible_keys: NULL
          key: idx_vehicle_prod_fin
      key_len: 203
          ref: NULL
         rows: 3182812
     filtered: 11.11
        Extra: Using where; Using index
1 row in set, 1 warning (0.00 sec)
</pre>

其中：
*id	select_id	The SELECT identifier
*select_type	None	The SELECT type
*table	table_name	The table for the output row
*partitions	partitions	The matching partitions
*type	access_type	The join type
*possible_keys	possible_keys	The possible indexes to choose
*key	key	The index actually chosen
*key_len	key_length	The length of the chosen key
*ref	ref	The columns compared to the index
*rows	rows	Estimate of rows to be examined
*filtered	filtered	Percentage of rows filtered by table condition
*Extra	None	Additional information


#https://dev.mysql.com/doc/refman/8.0/en/explain-output.html
[[Category:Datebase]]