mysql - difference in performance in Primary Key -


मेरे पास 4 कॉलम के साथ एक टेबल है: 

  id1 int id2 पाठ या varChar प्रकार टाइमस्टैम्प   
 प्राथमिक कुंजी  (आईडी 1, आईडी 2, प्रकार)  है और मैं  (आईडी 2, आईडी 1, प्रकार)  में बदलना चाहता हूं।  
 प्रदर्शन में अंतर क्या होगा? शायद यह प्रदर्शन की चाबी के समान होगा?   
 
 
 इस तरह की प्राथमिक कुंजी को न जोड़ें, प्राथमिक कुंजी के लिए लंबे / पूर्णांक मान का उपयोग करें, या यदि आपके डेटाबेस में कोई अनुक्रम है। 
 और, अगर आप कॉलम या एक संयोजन बनाना चाहते हैं कॉलम अद्वितीय होने के लिए, बस इसे चिह्नित करें या उन्हें अनूठे के रूप में जोड़ दें। 
 और साथ ही, कॉलम के लिए जो कि प्राथमिक कुंजी नहीं हैं, यदि आप की आवश्यकता होती है, तो आप इसे या उनमें इंडेक्स कुंजी भी जोड़ सकते हैं।

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