固定長データ型のサイズを以下に示します。
| データ型 | サイズ(バイト) | 
|---|---|
| SMALLINT(INT2) | 2 | 
| INTEGER(INT4) | 4 | 
| BIGINT(INT8) | 8 | 
| REAL | 4 | 
| DOUBLE PRECISION | 8 | 
| SERIAL(SERIAL4) | 4 | 
| BIGSERIAL(SERIAL8) | 8 | 
| MONEY | 8 | 
| FLOAT | 8 | 
| FLOAT(1-24) | 4 | 
| FLOAT(25-53) | 8 | 
| TIMESTAMP WITHOUT TIME ZONE | 8 | 
| TIMESTAMP WITH TIME ZONE | 8 | 
| DATE | 4 | 
| TIME WITHOUT TIME ZONE | 8 | 
| TIME WITH TIME ZONE | 12 | 
| INTERVAL | 12 | 
| BOOLEAN | 1 | 
| CIDR | IPv4の場合:7 | 
| INET | IPv4の場合:7 | 
| MACADDR | 6 | 
| MACADDR8 | 8 | 
| POINT | 16 | 
| LINE | 32 | 
| LSEG | 32 | 
| BOX | 32 | 
| CIRCLE | 24 |