mysql - mysqlビューが超遅い

Question

これは、正規化された単語に関連する単語を見つけるための統合医療言語システム (UMLS) のクエリです。このクエリの結果は 165 ミリ秒ですが、同じクエリの VIEW を実行すると 70 秒かかります。私はmysqlが初めてです。私を助けてください。

クエリ:

SELECT a.nwd as Normalized_Word, 
       b.str as String, 
       c.def as Defination, 
       d.sty as Semantic_type 
FROM mrxnw_eng a, mrconso b, mrdef c, mrsty d 
WHERE a.nwd = 'cold' 
     AND b.sab = 'Msh'
     AND a.cui = b.cui 
     AND a.cui = c.cui
     AND a.cui = d.cui
     AND a.lui = b.lui
     AND b.sui = a.sui
group by a.cui

ビューの定義:

create view nString_Sementic as 
SELECT a.nwd as Normalized_Word, 
       b.str as String, 
       c.def as Defination, 
       d.sty as Semantic_type 
FROM mrxnw_eng a, mrconso b, mrdef c, mrsty d 
WHERE b.sab = 'Msh'
     AND a.cui = b.cui 
     AND a.cui = c.cui
     AND a.cui = d.cui
     AND a.lui = b.lui
     AND b.sui = a.sui
group by a.cui   

ビューからの選択:

 select * nString_Sementic   
 where nwd = 'phobia'