Memory requirements of a column value per data types
Data type
Column definition
|
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 |