Does anyone have considerable proof that CHAR is faster than VARCHAR?

Question

Any benchmark, graph anything at all ? Its all academic and theoretical across the web.

Ok its not the first time that this question has been asked, they all say th

Answer 1

CHAR will be faster as it is fixed length. For example CHAR(10) and VARCHAR(10) CHAR(10) is a fixed-length string of 10 while VARCHAR is a variable-length string with maximum length of 10.

VARCHAR(10)

 {Index} (Length) [String]
 -------------------------
 {0} (8) [AAAAAAAA]
 {1} (5) [BBBBB]
 {2} (3) [CCC]
 {3} (7) [DDDDDDD]
 {4} (2) [EE]
 {5} (4) [FFFF]

CHAR(10)

 {Index} (Length) [String]
 -------------------------
 {0} (10) [AAAAAAAA  ]
 {1} (10) [BBBBB     ]
 {2} (10) [CCC       ]
 {3} (10) [DDDDDDD   ]
 {4} (10) [EE        ]
 {5} (10) [FFFF      ]

So imagine you have a table with 1,000,000 records and you need to get a record at offset 500,000.

CHAR - database engine would have to do multiply 500,000 x 10 = offset is 5,000,000.

VARCHAR - database engine would have to get each row length and sum them all 5 + 8 + 9 + 3 + 2 + 4... 500,000 times to get offset

CHAR padding is x00 which basically is end of the string so CHAR(10) = [A,A,A,A,A,00,00,00,00,00] is "AAAAA".