Memory requirements of a column value per data types
Data Type |
Memory Requirements of a Column Value in Bytes for This Data Type |
FIXED(p,s) |
(p+1) DIV 2 + 2 |
FLOAT(p) |
(p+1) DIV 2 + 2 |
BOOLEAN |
2 |
DATE |
9 |
TIME |
9 |
TIMESTAMP |
21 |
LONG |
9 |
CHAR(n); n<=30 |
n+1 |
CHAR(n); 30<n<=254; key column |
n+1 |
CHAR(n); 30<n<=254; not key column |
n+2 |
CHAR(n); 254<n |
n+3 |
CHAR(n) UNICODE; n<=15 |
2*n+1 |
CHAR(n) UNICODE; 15<n<=127; key column |
2*n+1 |
CHAR(n) UNICODE; 15<n<=127; not key column |
2*n+2 |
CHAR(n) UNICODE; 127<n |
2*n+3 |
VARCHAR(n); 30<n<=254; key column |
n+1 |
VARCHAR(n); 30<n<=254; not key column |
n+2 |
VARCHAR(n); 254<n |
n+3 |
VARCHAR(n) UNICODE; 15<n<=127; key column |
2*n+1 |
VARCHAR(n) UNICODE; 15<n<=127; not key column; |
2*n+2 |
VARCHAR(n) UNICODE; 127<n |
2*n+3 |