This topic describes the data types that are supported by Realtime Compute for Apache Flink and how to convert between different data types.
Data types supported by Realtime Compute for Apache Flink
Data type  Description  Value range 

VARCHAR  Stores strings of varying length.  A VARCHAR string can store a maximum of 4 MB of data. 
BOOLEAN  Stores logical values.  Valid values: TRUE, FALSE, and UNKNOWN. 
TINYINT  Stores tiny integers. Each tiny integer occupies 1 byte.  128 to 127 .

SMALLINT  Stores small integers. Each small integer occupies 2 bytes.  32768 to 32767 .

INT  Stores integers. Each integer occupies 4 bytes.  2147483648 to 2147483647 .

BIGINT  Stores big integers. Each big integer occupies 8 bytes.  9223372036854775808 to 9223372036854775807 .

FLOAT  Stores singleprecision floatingpoint numbers. Each singleprecision floatingpoint number occupies 4 bytes.  Each singleprecision floatingpoint number is accurate to six decimal places. 
DECIMAL  Stores the numbers that have the fixed precision and scale. The precision specifies the total number of digits both to the left and to the right of the decimal point. The scale specifies the number of digits to the right of the decimal point.  For example, the value of DECIMAL(5,2) is 123.45 .

DOUBLE  Stores doubleprecision floatingpoint numbers. Each doubleprecision floatingpoint number occupies 8 bytes.  Each doubleprecision floatingpoint number is accurate to 15 decimal places. 
DATE  Stores dates.  Example value: DATE'19690720' .

TIME  Stores time.  Example value: TIME '20:17:40' .

TIMESTAMP  Stores timestamps. Each timestamp contains both date and time.  Example value: TIMESTAMP '19690720 20:17:40' .

VARBINARY  Stores binary data.  This type corresponds to the byte[] array.
Note The storage size for the VARBINARY data type is not limited.

Data type conversion
Example
 Test data
var1 (VARCHAR) big1 (BIGINT) 1000 323  Test statements
cast (var1 as bigint) as AA; cast (big1 as varchar) as BB;
 Test results
AA (BIGINT) BB (VARCHAR) 1000 323