MySQL is an SQL statement optimization, what to do with

An SQL statement optimization for MySQL
SELECT t_wenzhang.contents, T_wenzhang.createtime, T_wenzhang.title,t_wenzhang.pagepath from T_wenzhang left JOIN T_ Keys on t_keys.id = T_wenzhang.keyword where SUBSTRING (KEYP, 1, 1) = ' "+ Zimu +" ' ORDER BY createtime Desc






Above the T_wenzhang table 4 W data, T_keys 3W, how this executes in + + seconds! If and optimization!
------Solution--------------------
The first is to index the 4 fields of T_keys.id,t_wenzhang.keyword,keyp,zimu
Second, if it's slow, try to change the engine.
Finally, you can use Explan to help select better indexes and write more optimized query statements!

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