NUMERIC data types

Informix^® supports several data types to store numbers:

Table 1. Informix numeric data types
Informix data type	Description
SMALLINT	16 bit signed integer
INT / INTEGER	32 bit signed integer
BIGINT	64 bit signed integer
INT8	64 bit signed integer (replaced by BIGINT)
DEC / DECIMAL	Equivalent to DECIMAL(16)
DEC / DECIMAL(p)	Floating-point decimal number
DEC / DECIMAL(p,s)	Fixed-point decimal number
MONEY	Equivalent to DECIMAL(16,2)
MONEY(p)	Equivalent to DECIMAL(p,2)
MONEY(p,s)	Equivalent to DECIMAL(p,s)
REAL / SMALLFLOAT	32-bit floating point decimal (C float)
DOUBLE PRECISION / FLOAT[(n)]	64-bit floating point decimal (C double)

Solution

PostgreSQL supports the following data types to store numbers:

Table 2. PostgreSQL numeric data types
PostgreSQL data type	Description
NUMERIC(p,s) / DECIMAL(p,s)	Decimals with precision and scale (fractional part)
NUMERIC(p) / DECIMAL(p)	Integers with p digits (no fractional part)
NUMERIC / DECIMAL	Floating point numbers (no limit)
FLOAT4	16 bit variable precision
FLOAT8	32 bit variable precision
INT2	16 bit signed integer
INT4	32 bit signed integer
INT8/BIGINT	64 bit signed integer

ANSI types like SMALLINT, INTEGER, FLOAT are supported by PostgreSQL as aliases to INT2, INT4 and FLOAT8 native types.

Informix DECIMAL(p) floating point types are converted to DECIMAL without precision/scale, to store any floating point number in PostgreSQL.