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Numeral

Table 1 lists all available types. For digit operators and related built-in functions, see Mathematical Functions and Operators.

Table 1 Integer types

Name

Description

Storage (GB)

Range

TINYINT

Tiny integer, also called INT1

1 byte

0–255

SMALLINT

Small integer, also called INT2

2 bytes

-32,768–+32,767

INTEGER

Typical choice for integer, also called INT4

4 bytes

-2,147,483,648–+2,147,483,647

BINARY_INTEGER

Alias of INTEGER, compatible with Oracle

4 bytes

-2,147,483,648–+2,147,483,647

BIGINT

Big integer, also called INT8

8 bytes

-9,223,372,036,854,775,808–9,223,372,036,854,775,807

Example:

-- Create a table containing TINYINT data.
CREATE TABLE int_type_t1
           (
            IT_COL1 TINYINT
           ) ;

-- Create a table containing TINYINT data.
INSERT INTO int_type_t1 VALUES(10);

-- View data.
SELECT * FROM int_type_t1;
 it_col1  
--------- 
 10
(1 row)

-- Delete the table.
DROP TABLE int_type_t1;
-- Create a table containing TINYINT, INTEGER, and BIGINT data.
CREATE TABLE int_type_t2 
(
    a TINYINT, 
    b TINYINT,
    c INTEGER,
    d BIGINT
);

-- Insert data.
INSERT INTO int_type_t2 VALUES(100, 10, 1000, 10000);

-- View data.
SELECT * FROM int_type_t2;
  a  | b  |  c   |   d   
-----+----+------+-------
 100 | 10 | 1000 | 10000
(1 row)

-- Delete the table.
DROP TABLE int_type_t2;
NOTE:
  • The TINYINT, SMALLINT, INTEGER, and BIGINT types store whole numbers, that is, numbers without fractional components, of various ranges. Saving a number with a decimal in any of the data types will result in errors.
  • The INTEGER type is the common choice, as it offers the best balance between range, storage size, and performance. Generally, use the SMALLINT type only if you are sure that the value range is within the SMALLINT value range. The storage speed of INTEGER is much faster. BIGINT is used only when the range of INTEGER is not large enough.
Table 2 Any-precision types

Name

Description

Storage (GB)

Range

NUMERIC[(p[,s])],

DECIMAL[(p[,s])]

The value range of p (precision) is [1,1000], and the value range of s (standard) is [0,p].

NOTE:

p indicates the total digits, and s indicates the decimal digit.

The precision is specified by users. Every four decimal digits occupy two bytes, and an extra eight-byte overhead is added to the entire data.

Up to 131,072 digits before the decimal point; and up to 16,383 digits after the decimal point when no precision is specified

NUMBER[(p[,s])]

Alias for type numeric. This is a compatible Oracle data type.

The precision is specified by users. Every four decimal digits occupy two bytes, and an extra eight-byte overhead is added to the entire data.

Up to 131,072 digits before the decimal point; and up to 16,383 digits after the decimal point when no precision is specified

Example:

-- Create a table.
CREATE TABLE decimal_type_t1 
(
    DT_COL1 DECIMAL(10,4)
);

-- Insert data.
INSERT INTO decimal_type_t1 VALUES(123456.122331);

-- Query data in the table.
SELECT * FROM decimal_type_t1;
   dt_col1   
-------------
 123456.1223
(1 row)

-- Delete the table.
DROP TABLE decimal_type_t1;
-- Create a table.
CREATE TABLE numeric_type_t1 
(
    NT_COL1 NUMERIC(10,4)
);

-- Insert data.
INSERT INTO numeric_type_t1 VALUES(123456.12354);

-- Query data in the table.
SELECT * FROM numeric_type_t1;
   nt_col1   
-------------
 123456.1235
(1 row)

-- Delete the table.
DROP TABLE numeric_type_t1;
NOTE:
  • Compared to the integer types, the arbitrary precision numbers require larger storage space and have lower storage efficiency, operation efficiency, and poorer compression ratio results. The INTEGER type is the common choice when number types are defined. Arbitrary precision numbers are used only when numbers exceed the maximum range indicated by the integers.
  • When NUMERIC/DECIMAL is used for defining a column, you are advised to specify the precision (p) and scale (s) for the column.
Table 3 Sequence integer

Name

Description

Storage (GB)

Range

SMALLSERIAL

Two-byte auto-incrementing integer

2 bytes

1–32,767

SERIAL

Four-byte auto-incrementing integer

4 bytes

1–2,147,483,647

BIGSERIAL

Eight-byte auto-incrementing integer

8 bytes

1–9,223,372,036,854,775,807

Example:

-- Create a table.
CREATE TABLE smallserial_type_tab(a SMALLSERIAL);

-- Insert data.
INSERT INTO smallserial_type_tab VALUES(default);

-- Insert data again.
INSERT INTO smallserial_type_tab VALUES(default);

-- View data.
SELECT * FROM smallserial_type_tab;  
 a 
---
 1
 2
(2 rows)

-- Create a table.
CREATE TABLE serial_type_tab(b SERIAL);

-- Insert data.
INSERT INTO serial_type_tab VALUES(default);

-- Insert data again.
INSERT INTO serial_type_tab VALUES(default);

-- View data.
SELECT * FROM serial_type_tab; 
 b 
---
 1
 2
(2 rows)

-- Create a table.
CREATE TABLE bigserial_type_tab(c BIGSERIAL);

-- Insert data.
INSERT INTO bigserial_type_tab VALUES(default);

-- Insert data.
INSERT INTO bigserial_type_tab VALUES(default);

-- View data.
SELECT * FROM bigserial_type_tab;
 c 
---
 1
 2
(2 rows)

-- Delete the tables.
DROP TABLE smallserial_type_tab;

DROP TABLE serial_type_tab;

DROP TABLE bigserial_type_tab;
NOTE:

SMALLSERIAL, SERIAL, and BIGSERIAL are not real types. They are concepts used for setting a unique identifier for a table. Therefore, an integer column is created and its default value plans to be read from a sequencer. A NOT NULL constraint is used to ensure NULL is not inserted. In most cases you would also want to attach a UNIQUE or PRIMARY KEY constraint to prevent duplicate values from being inserted unexpectedly, but this is not automatic. The sequencer is set so that it belongs to the column. In this case, when the column or the table is deleted, the sequencer is also deleted. Currently, the SERIAL column can be specified only when you create a table. You cannot add the SERIAL column in an existing table. In addition, SERIAL columns cannot be created in temporary tables. Because SERIAL is not a data type, columns cannot be converted to this type.

Table 4 Floating point types

Name

Description

Storage (GB)

Range

REAL,

FLOAT4

Single precision floating points, inexact

4 bytes

Six bytes of decimal digits

DOUBLE PRECISION,

FLOAT8

Double precision floating points, inexact

8 bytes

1E-307 to 1E+308,

15 bytes of decimal digits

FLOAT[(p)]

Floating points, inexact. The value range of precision (p) is [1,53].

NOTE:

p is the precision, indicating the total decimal digits.

4 or 8 bytes

REAL or DOUBLE PRECISION is selected as an internal identifier based on different precision (p). If no precision is specified, DOUBLE PRECISION is used as the internal identifier.

BINARY_DOUBLE

DOUBLE PRECISION alias, compatible with Oracle

8 bytes

1E-307 to 1E+308,

15 bytes of decimal digits

DEC[(p[,s])]

The value range of p (precision) is [1,1000], and the value range of s (standard) is [0,p].

NOTE:

p indicates the total digits, and s indicates the decimal digit.

The precision is specified by users. Every four decimal digits occupy two bytes, and an extra eight-byte overhead is added to the entire data.

Up to 131,072 digits before the decimal point; and up to 16,383 digits after the decimal point when no precision is specified

INTEGER[(p[,s])]

The value range of p (precision) is [1,1000], and the value range of s (standard) is [0,p].

The precision is specified by users. Every four decimal digits occupy two bytes, and an extra eight-byte overhead is added to the entire data.

Up to 131,072 digits before the decimal point; and up to 16,383 digits after the decimal point when no precision is specified

Example:

-- Create a table.
CREATE TABLE float_type_t2 
(
    FT_COL1 INTEGER,
    FT_COL2 FLOAT4,
    FT_COL3 FLOAT8,
    FT_COL4 FLOAT(3),
    FT_COL5 BINARY_DOUBLE,
    FT_COL6 DECIMAL(10,4),
    FT_COL7 INTEGER(6,3)
) DISTRIBUTE BY HASH ( ft_col1);

-- Insert data.
INSERT INTO float_type_t2 VALUES(10,10.365456,123456.1234,10.3214, 321.321, 123.123654, 123.123654);

-- View data.
SELECT * FROM float_type_t2 ;
 ft_col1 | ft_col2 |   ft_col3   | ft_col4 | ft_col5 | ft_col6  | ft_col7 
---------+---------+-------------+---------+---------+----------+---------
      10 | 10.3655 | 123456.1234 | 10.3214 | 321.321 | 123.1237 | 123.124
(1 row)

-- Delete the tables.
DROP TABLE float_type_t2;