[استفسار] هل تؤثر دالة كثرة استخدام استعلامات union على السيرفر
 

لدي استعلام بالشكل الاتي

رمز Code:
(SELECT * FROM `comments` WHERE `userid` = '1' LIMIT 5) UNION
(SELECT * FROM `comments` WHERE `userid` = '2' LIMIT 5) UNION
(SELECT * FROM `comments` WHERE `userid` = '3' LIMIT 5) UNION
(SELECT * FROM `comments` WHERE `userid` = '4' LIMIT 5) UNION
(SELECT * FROM `comments` WHERE `userid` = '5' LIMIT 5) UNION
(SELECT * FROM `comments` WHERE `userid` = '6' LIMIT 5) UNION
(SELECT * FROM `comments` WHERE `userid` = '7' LIMIT 5) UNION
(SELECT * FROM `comments` WHERE `userid` = '8' LIMIT 5) UNION
(SELECT * FROM `comments` WHERE `userid` = '9' LIMIT 5) UNION



(SELECT * FROM `comments` WHERE `userid` = '10' LIMIT 5) ;
وقد يصل الى 30 أمر مدمجة بجملة UNION
هل يؤثر هذا على السيرفر

وهل توجد طريقة اخرى لتنفيذ هذا الاستعلام ؟