Source typeTarget typeFunction (1)Implicit?
INT8INT4INT4In assignment
INT8INT2INT2In assignment
INT8DECIMALDECIMALyes
INT8FLOAT8FLOAT8yes
INT8FLOAT4FLOAT4yes
INT8BOOLEANBOOLno
INT8VARCHARTEXTIn assignment
INT4INT8INT8yes
INT4INT2INT2In assignment
INT4DECIMALDECIMALyes
INT4FLOAT8FLOAT8yes
INT4FLOAT4FLOAT4yes
INT4BOOLEANBOOLno
INT4VARCHARTEXTIn assignment
INT2INT8INT8yes
INT2INT4INT4yes
INT2DECIMALDECIMALyes
INT2FLOAT8FLOAT8yes
INT2FLOAT4FLOAT4yes
INT2BOOLEANBOOLno
INT2VARCHARTEXTIn assignment
DECIMALINT8INT8In assignment
DECIMALINT4INT4In assignment
DECIMALINT2INT2In assignment
DECIMALDECIMALDECIMALyes
DECIMALFLOAT8FLOAT8yes
DECIMALFLOAT4FLOAT4yes
DECIMALVARCHARTEXTIn assignment
FLOAT8INT8INT8In assignment
FLOAT8INT4INT4In assignment
FLOAT8INT2INT2In assignment
FLOAT8DECIMALDECIMALIn assignment
FLOAT8FLOAT4FLOAT4In assignment
FLOAT8VARCHARTEXTIn assignment
FLOAT4INT8INT8In assignment
FLOAT4INT4INT4In assignment
FLOAT4INT2INT2In assignment
FLOAT4DECIMALDECIMALIn assignment
FLOAT4FLOAT8FLOAT8yes
FLOAT4VARCHARTEXTIn assignment
VARCHARCHARACTERnone (2)yes
VARCHARVARCHARTEXTyes
CHARACTER (3)CHARACTERBPCHARyes
CHARACTERVARCHARTEXTyes
BOOLEANINT8INT8no
BOOLEANINT4INT4no
BOOLEANINT2INT2no
BOOLEANVARCHARTEXTIn assignment
BOOLEANCHARACTERnoneIn assignment
TIMESTAMPVARCHARTEXTIn assignment
TIMESTAMPDATEDATEIn assignment
TIMESTAMPTIMETIMEIn assignment
DATEVARCHARTEXTIn assignment
DATETIMESTAMPTIMESTAMPyes
TIMEVARCHARTEXTIn assignment

Notes:

(1) Function: The name of an explicit conversion function (e.g SELECT FLOAT8(5.2)) (2) ‘none’ means there is no explicit conversion function for this case. (3) Conversion from CHAR(n) to the CHAR(m) where M != n.