Does a unique constraint make hashes useless?

Am I confused if MySQL has a unique constraint - is it a physical index or virtual index? And since a unique constraint is defined for the column, is there a need to create a hash column and determine the index in the hash column to speed up the query process, given that the unique constraint column contains a variable number of characters, mostly more than 40 characters, and an average of 50 +?

And the total number of entries is 150+ million plus.

I asked another question with the details of the hashes and its indexing plan. pointer to URL or RAM hashed

0
source share
1 answer

, , . , , , , . 150 , , 256- , 18 , 50 avg. , 2 , 4 .

+1

All Articles