What is a UUID? UUID vs. GUID 

UUID V4 --> generates random UUID 128 bit based on some algo , chances pf collision is less , given the permutations. so if there are 5000 records in a table lets say uuid column is primary key and index , then we need to do fast search(index) using the column for duplicate and if no duplication allow .Math.pow(2,128) uuid can be generated .

The best video ❤it.

1:25 Hexadecimal? I see that there are letters in the example outside the hexadecimal range.

thanks for this simple explanation

TimeUUIDs have examples of applications where collisions are not negligible

Thanks for the video, just one question. Is there any way to discern the date and time using a UUID?

1:27 my eyes are twitching... THOSE ARE NOT HEXADECIMAL DIGITS

What happens if a collision occurs though

Thanks for this explanation. I prefer UUID v4 because of the anonimity.

cant wait for y3.4k assuming we live that long

i am genrate UUID using python with following syntax "subprocess.check_output('wmic csproduct get uuid').decode().split(' ')[1].strip()". It generated like "C50A0704-1C0B-FE5B-B792-D017C2D25XXX" . Please explain me how this combination generated and also it is unique? How it is generate automatically ?

If i share my pc system uuid(Wmic csproduct get uuid) then my pc can be hack?

Use V4 , it will provide you with the much needed anonymity , that's a pro . Of course , the con is the probability of collisions happening , but , one way of mitigating this , is on server side , whenever we generate a uuid we just search an array containing all uuid generated , and we filter() or some() to do basic checking if it exists then we can push it in the array then send it to the client . Which is a good approach but will be costly in time n space , so we can use instead a Set() and each time we generate a uuid before we push it directly , we just check the set length , then we add() the uuid to the set , then recheck the length , if it's same to previous , it means the uuid exists , that means we need to regenerate it , if the length is +1 , it means it's not taken and we can safely use our V4 uuid without even worrying about collisions , this second technique will result in better performance , and better big O .

You say there are variant 0 through 2, then proceed to explain version 4. What gives?

v4

The authors of the video don't know what they're talking about.