Storage Requirements for Numeric Types
Data Type | Storage Required |
---|---|
TINYINT | 1 byte |
SMALLINT | 2 bytes |
MEDIUMINT | 3 bytes |
INT , INTEGER | 4 bytes |
BIGINT | 8 bytes |
FLOAT( | 4 bytes if 0 <= p <= 24, 8 bytes if 25 <= p <= 53 |
FLOAT | 4 bytes |
DOUBLE [PRECISION] , REAL | 8 bytes |
DECIMAL( , NUMERIC( | Varies; see following discussion |
BIT( | approximately (M +7)/8 bytes |
Data Type | Storage Required |
---|---|
DATE | 3 bytes |
TIME | 3 bytes |
DATETIME | 8 bytes |
TIMESTAMP | 4 bytes |
YEAR | 1 byte |
Storage Requirements for String Types
In the following table, M
represents the declared column length in characters for nonbinary string types and bytes for binary string types. L
represents the actual length in bytes of a given string value.
Data Type | Storage Required |
---|---|
CHAR( | M × w bytes, 0 <= 255, where w is the number of bytes required for the maximum-length character in the character set |
BINARY( | M bytes, 0 <= 255 |
VARCHAR( , VARBINARY( | L + 1 bytes if column values require 0 – 255 bytes, L + 2 bytes if values may require more than 255 bytes |
TINYBLOB , TINYTEXT | L + 1 bytes, where L < 28 |
BLOB , TEXT | L + 2 bytes, where L < 216 |
MEDIUMBLOB , MEDIUMTEXT | L + 3 bytes, where L < 224 |
LONGBLOB , LONGTEXT | L + 4 bytes, where L < 232 |
ENUM(' | 1 or 2 bytes, depending on the number of enumeration values (65,535 values maximum) |
SET(' | 1, 2, 3, 4, or 8 bytes, depending on the number of set members (64 members maximum) |
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