This is the slide of a session at the biggest tech conference in south Taiwan. The session would introduce how to improve efficiency on the web application & database side. This slide use Mandarin

1. 現代 WEB 框架效能優化技巧分享
John Liu

2. 2
Netskope, Full stack engineer
AppWorks School, Backend Instructor
Leetcode, Content Author
Freelance lecturer ( 上市櫃企業、⼤專院校、補習班、線上平台... )
John Liu

3. Effectiveness Category
應⽤程式
資料庫
速度
記憶體

4. Speci
fi
cation

5. Chunk
10000 筆 rows，平均 query 時間約差 2 倍

6. Take care high-level function

7. Cursor
90000 筆 rows，平均記憶體使⽤量約差 2 倍，但 query 時間約多了 20%

8. Generator syntax

9. Select "Your Need"
323695 筆資料、27個欄位
假設只顯⽰ 5 個欄位，顯⽰資料時間降低超過 80%: 52s --> 9s

10. Data type transform
90000 筆 rows，平均記憶體使⽤量約差 11 倍，但執⾏時間約多了 50%

11. About "toArray()"
90000 筆 rows，平均記憶體使⽤量約差 2 倍，但執⾏時間約多了 50%

12. Count by database instead of application
90000 筆 rows，平均記憶體使⽤量約差 2.5 倍，執⾏時間約多了 100 倍

13. N + 1 Query solution ( Eager Loading )
90000 筆 row
s
Old: 建立資料: 8.7s、跑完 Query: 147s，memory 500 MB ( query 會⽤
)
New: 建立資料: 14s、跑完 Query: 4s，memory 150 MB

14. Using FK instead of key of relation

15. Logic accuration

16. Index
90000 筆 rows，每列皆不同，無 index 0.036s，有 index 0.00055
s
差距約 60 倍

21. TempTable

22. Pagination
90000 筆 rows 的 count query 約需 0.01s

23. Schema Design
過多欄位 過⼤的欄位

24. MonitorTool

29. Task 1
Task 2
Task 3
Task 1
Task 2
Task 3
Blocking I/O NonBlocking I/O
Time

31. Sandbox

32. HTTP Cache
With
Without

37. What we can do more !?

38. Explain

39. window function

40. Server...