brunoocasali

-- Criei uma função para melhorar a legibilidade:

CREATE FUNCTION `age_group_from` (birthday DATE)
RETURNS TEXT
BEGIN
   DECLARE age_group VARCHAR(5); 
   
   SET age_group = CASE
	  WHEN TIMESTAMPDIFF(YEAR, birthday, NOW()) >= 40 THEN '≥ 40'
	  WHEN TIMESTAMPDIFF(YEAR, birthday, NOW()) BETWEEN 20 AND 39 THEN '20-39'

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs