Datatype Mapping

db2_fdw maps DB2 data types to PG data types

DB2 DATA TYPE	SQL DATA TYPE	PG DATA TYPE
VARCHAR	SQL_VARCHAR	character varying()
LONG VARCHAR && CODEPAGE != 0	SQL_LONGVARCHAR	text
LONG VARCHAR && CODEPAGE == 0	SQL_LONGVARBINARY	bytea
CHARACTER	SQL_CHAR	character()
BINARY	SQL_BINARY	bytea
VARBINARY	SQL_VARBINARY	bytea
SMALLINT	SQL_SMALLINT	smallint
INTEGER	SQL_INTEGER	integer
BIGINT	SQL_BIGINT	bigint
DATE	SQL_TYPE_DATE	date
TIMESTAMP	SQL_TYPE_TIMESTAMP	timestamp()
TIME	SQL_TYPE_TIME	time()
XML	SQL_XML	xml
BLOB	SQL_BLOB	bytea
CLOB	SQL_CLOB	text
DECIMAL	SQL_DECIMAL	decimal(,)
GRAPHIC	SQL_GRAPHIC	text
VARGRAPHIC	SQL_VARGRAPHIC	text
DECFLOAT	SQL_DECFLOAT	float()
DOUBLE	SQL_DOUBLE	double precision
REAL	SQL_REAL	real
FLOAT	SQL_FLOAT	float()
BOOLEAN	SQL_BOOLEAN	boolean

PG restrictions:

• "text" and "bytea" columns have a limitation to a size of 1GB, whereas DB2 LOB columns may be able to exceed that limit.
• "float" is able to host DB2 DECFLOAT values but only up to DECFLOAT 16. DECFLOAT 34 is not supported in PG float.