Type conversion table

Source type	Target type	Function (1)	Implicit?
INT8	INT4	INT4	In assignment
INT8	INT2	INT2	In assignment
INT8	DECIMAL	DECIMAL	yes
INT8	FLOAT8	FLOAT8	yes
INT8	FLOAT4	FLOAT4	yes
INT8	BOOLEAN	BOOL	no
INT8	VARCHAR	TEXT	In assignment
INT4	INT8	INT8	yes
INT4	INT2	INT2	In assignment
INT4	DECIMAL	DECIMAL	yes
INT4	FLOAT8	FLOAT8	yes
INT4	FLOAT4	FLOAT4	yes
INT4	BOOLEAN	BOOL	no
INT4	VARCHAR	TEXT	In assignment
INT2	INT8	INT8	yes
INT2	INT4	INT4	yes
INT2	DECIMAL	DECIMAL	yes
INT2	FLOAT8	FLOAT8	yes
INT2	FLOAT4	FLOAT4	yes
INT2	BOOLEAN	BOOL	no
INT2	VARCHAR	TEXT	In assignment
DECIMAL	INT8	INT8	In assignment
DECIMAL	INT4	INT4	In assignment
DECIMAL	INT2	INT2	In assignment
DECIMAL	DECIMAL	DECIMAL	yes
DECIMAL	FLOAT8	FLOAT8	yes
DECIMAL	FLOAT4	FLOAT4	yes
DECIMAL	VARCHAR	TEXT	In assignment
FLOAT8	INT8	INT8	In assignment
FLOAT8	INT4	INT4	In assignment
FLOAT8	INT2	INT2	In assignment
FLOAT8	DECIMAL	DECIMAL	In assignment
FLOAT8	FLOAT4	FLOAT4	In assignment
FLOAT8	VARCHAR	TEXT	In assignment
FLOAT4	INT8	INT8	In assignment
FLOAT4	INT4	INT4	In assignment
FLOAT4	INT2	INT2	In assignment
FLOAT4	DECIMAL	DECIMAL	In assignment
FLOAT4	FLOAT8	FLOAT8	yes
FLOAT4	VARCHAR	TEXT	In assignment
VARCHAR	CHARACTER	none (2)	yes
VARCHAR	VARCHAR	TEXT	yes
CHARACTER (3)	CHARACTER	BPCHAR	yes
CHARACTER	VARCHAR	TEXT	yes
BOOLEAN	INT8	INT8	no
BOOLEAN	INT4	INT4	no
BOOLEAN	INT2	INT2	no
BOOLEAN	VARCHAR	TEXT	In assignment
BOOLEAN	CHARACTER	none	In assignment
TIMESTAMP	VARCHAR	TEXT	In assignment
TIMESTAMP	DATE	DATE	In assignment
TIMESTAMP	TIME	TIME	In assignment
DATE	VARCHAR	TEXT	In assignment
DATE	TIMESTAMP	TIMESTAMP	yes
TIME	VARCHAR	TEXT	In 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.