Tipos de dados numéricos¶

This topic describes the numeric data types supported in Snowflake, along with the supported formats for numeric constants and literals.

Tipos de dados para números de ponto fixo¶

O Snowflake oferece suporte aos seguintes tipos de dados para números de ponto fixo.

NUMBER¶

Números até 38 dígitos, com precisão e escala opcionais:

Precisão:: Número total de dígitos permitidos.
Escala:: Número de dígitos permitidos à direita da vírgula decimal.

By default, precision is 38, and scale is 0; that is, NUMBER(38, 0). Precision limits the range of values that can be inserted into or cast to columns of a given type. For example, the value 999 fits into NUMBER(38,0) but not into NUMBER(2,0).

Because precision is the total number of digits allowed, you can’t load a value into a NUMBER column if the number of digits to the left of the decimal point exceeds the precision of the column minus its scale. For example, NUMBER(20, 2) allows 18 digits on the left side of the decimal point and two digits on the right side of the decimal point, for a total of 20 digits.

The maximum scale, which is the number of digits to the right of the decimal point, is 37. Numbers that have fewer than 38 significant digits, but whose least significant digit is past the 37th decimal place — for example, 0.0000000000000000000000000000000000000012 (1.2e-39) — can’t be represented without losing some digits of precision.

Nota

If data is converted to another data type with lower precision, and then converted back to the higher-precision data type, the data can lose precision. For example, precision is lost if you convert a NUMBER(38,37) value to a DOUBLE value — which has a precision of approximately 15 decimal digits — and then back to NUMBER.

O Snowflake também oferece suporte ao tipo de dados FLOAT, o que permite uma gama mais ampla de valores, embora com menos precisão.

DECIMAL , DEC , NUMERIC¶

Sinônimo de NUMBER.

INT , INTEGER , BIGINT , SMALLINT , TINYINT , BYTEINT¶

Sinônimo de NUMBER, exceto pelo fato de que a precisão e a escala não podem ser especificadas (ou seja, o padrão é sempre NUMBER(38, 0)). Portanto, para todos os tipos de dados INTEGER, o intervalo de valores abrange todos os valores inteiros a partir de -99999999999999999999999999999999999999 até +99999999999999999999999999999999999999 (inclusive).

The various names — for example, TINYINT, BYTEINT, and so on —are to simplify porting from other systems and to suggest the expected range of values for a column of the specified type.

Impacto da precisão e da escala no tamanho de armazenamento¶

Precision — the total number of digits — doesn’t affect storage. The storage requirements for the same number in columns with different precisions, such as NUMBER(2,0) and NUMBER(38,0), are the same. For each micro-partition, Snowflake determines the minimum and maximum values for a given column and uses that information to determine the storage size for all values for that column in the partition. For example:

If a column contains only values between -128 and +127, each of the values consumes 1 byte (uncompressed).
If the largest value in the column is 10000000, each of the values consumes 4 bytes (uncompressed).

However, scale — the number of digits following the decimal point — affects storage. For example, the same value stored in a column of type NUMBER(10,5) consumes more space than NUMBER(5,0). Also, processing values with a larger scale might be slightly slower and consume more memory.

Para economizar espaço, o Snowflake comprime os valores antes de gravá-los no armazenamento. A quantidade de compressão depende dos valores dos dados e de outros fatores.

Exemplos de tipos de dados de ponto fixo em uma tabela¶

A instrução a seguir cria uma tabela com colunas de vários tipos de dados de ponto fixo:

CREATE OR REPLACE TABLE test_fixed(
  num0 NUMBER,
  num10 NUMBER(10,1),
  dec20 DECIMAL(20,2),
  numeric30 NUMERIC(30,3),
  int1 INT,
  int2 INTEGER);

DESC TABLE test_fixed;

Copy

+-----------+--------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------+
| name      | type         | kind   | null? | default | primary key | unique key | check | expression | comment | policy name | privacy domain |
|-----------+--------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------|
| NUM0      | NUMBER(38,0) | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| NUM10     | NUMBER(10,1) | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| DEC20     | NUMBER(20,2) | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| NUMERIC30 | NUMBER(30,3) | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| INT1      | NUMBER(38,0) | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| INT2      | NUMBER(38,0) | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
+-----------+--------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------+

Tipos de dados para números de ponto flutuante¶

O Snowflake oferece suporte aos seguintes tipos de dados para números de ponto flutuante.

FLOAT , FLOAT4 , FLOAT8¶

Os nomes FLOAT, FLOAT4 e FLOAT8 são para fins de compatibilidade com outros sistemas. O Snowflake trata todos os três como números de ponto flutuante de 64 bits.

Precisão¶

O Snowflake utiliza números de ponto flutuante de precisão dupla (64 bits) IEEE 754.

Precision is approximately 15 digits. For example, for integers, the range is from -9007199254740991 to +9007199254740991 (-2⁵³ + 1 to +2⁵³ - 1). Floating-point values can range from approximately 10^-308 to 10⁺³⁰⁸. Snowflake can represent more extreme values between approximately 10^-324 and 10^-308 with less precision. For more details, see the Wikipedia article on double-precision numbers.

O Snowflake oferece suporte ao tipo de dados de ponto fixo NUMBER, que permite maior precisão, embora uma gama menor de expoentes.

Valores especiais¶

O Snowflake oferece suporte aos seguintes valores especiais para FLOAT:

'NaN' (não é um número)
'inf' (infinito)
'-inf' (infinito negativo)

Os símbolos 'NaN', 'inf' e '-inf' devem estar entre aspas simples e fazem a distinção entre maiúsculas e minúsculas.

A semântica comparativa para 'NaN' difere do padrão IEEE 754 das seguintes maneiras:

Condição	Snowflake	IEEE 754	Comentário
`'NaN' = 'NaN'`	`TRUE`	`FALSE`	No Snowflake, os valores `'NaN'` são todos iguais.
`'NaN' > X` . where `X` is any FLOAT value, including . infinity, other than `NaN` itself.	`TRUE`	`FALSE`	No Snowflake, `'NaN'` é maior . do que qualquer outro valor FLOAT, . incluindo infinito.

Erros de arredondamento¶

As operações de ponto flutuante podem apresentar pequenos erros de arredondamento nos dígitos menos significativos. Erros de arredondamento podem ocorrer em qualquer tipo de processamento de ponto flutuante, incluindo funções trigonométricas, estatísticas e geoespaciais.

The following list shows considerations for rounding errors:

Os erros podem variar a cada vez que a consulta é executada.
Os erros podem ser maiores quando os operandos têm precisão ou escala diferente.
Errors can accumulate, especially when aggregate functions —for example, SUM or AVG — process large numbers of rows. Casting to a fixed-point data type before aggregating can reduce or eliminate these errors.
Rounding errors can occur not only when working with SQL, but also when working with other code — for example, Java, JavaScript, or Python — that runs inside Snowflake — for example, in UDFs and stored procedures.
Ao comparar dois números de ponto flutuante, o Snowflake recomenda a comparação para uma igualdade aproximada, em vez de uma igualdade exata.

It might be possible to avoid these types of approximation errors by using the exact DECFLOAT data type.

DOUBLE , DOUBLE PRECISION , REAL¶

Sinônimo de FLOAT.

Exemplos de tipos de dados de ponto flutuante em uma tabela¶

A instrução a seguir cria uma tabela com colunas de vários tipos de dados de ponto flutuante:

CREATE OR REPLACE TABLE test_float(
  double1 DOUBLE,
  float1 FLOAT,
  dp1 DOUBLE PRECISION,
  real1 REAL);

DESC TABLE test_float;

Copy

+---------+-------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------+
| name    | type  | kind   | null? | default | primary key | unique key | check | expression | comment | policy name | privacy domain |
|---------+-------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------|
| DOUBLE1 | FLOAT | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| FLOAT1  | FLOAT | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| DP1     | FLOAT | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| REAL1   | FLOAT | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
+---------+-------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------+

Nota

The DESC TABLE command’s type column displays the data type FLOAT not only for FLOAT, but also for synonyms of FLOAT; for example, DOUBLE, DOUBLE PRECISION, and REAL.

DECFLOAT¶

The decimal float (DECFLOAT) data type stores numbers exactly, with up to 38 significant digits of precision, and uses a dynamic base-10 exponent to represent very large or small values. The exponent range is from -16383 to 16384, allowing values approximately between -10^(16384) and 10^(16384). The DECFLOAT data type supports a variable scale so that the scale varies depending on the specific value being stored. In contrast to the FLOAT data type, which represents values as approximations, the DECFLOAT data type represents exact values in the specified precision.

The DECFLOAT data type doesn’t support the following special values that are supported by the FLOAT data type: 'NaN' (not a number), 'inf' (infinity), and '-inf' (negative infinity).

Use cases for the DECFLOAT data type¶

Use the DECFLOAT data type when you need exact decimal results and a wide, variable scale in the same column.

The DECFLOAT data type is appropriate for the following general use cases:

You are ingesting data, and the scale of incoming numeric values is unknown or highly variable.
You require exact numeric values; for example, ledgers, taxes, or compliance.
You are migrating from systems that rely on the IEEE 754-decimal representation or 128-bit decimals. These migrations might be blocked by the precision or range limitations of other Snowflake data types.
You want to avoid Number out of representable range errors when you sum, multiply, or divide high-precision numeric values.

For example, you can use the DECFLOAT data type for the following specific use cases:

You are ingesting heterogeneously scaled data from Oracle DECIMAL or DB2 DECFLOAT columns.
You are performing financial modeling that involves computations with scales of results that are hard to predict.
You are running scientific measurements that swing from nano units to astronomical units.

You can continue to use the NUMBER data type for fixed-scale numeric columns or the FLOAT data type for high-throughput analytics where imprecise results are acceptable.

Usage notes for the DECFLOAT data type¶

If an operation produces a result with more than 38 digits, the DECFLOAT value is rounded to 38-digit precision, with the least-significant digits rounded off according to the current rounding mode. Snowflake uses the half up rounding mode for DECFLOAT values.
When you specify a DECFLOAT value or you cast to a DECFLOAT value, avoid using numeric literals in SQL. If you use numeric literals in SQL, the values are interpreted as NUMBER or FLOAT values before being cast to a DECFLOAT value, which can result in range errors or loss of exactness. Instead, use either string literals — such as SELECT '<value>'::DECFLOAT — or the DECFLOAT literal — such as SELECT DECFLOAT '<value>'.
When operations mix DECFLOAT values and values of other numeric types, coercion prefers the DECFLOAT values. For example, when you add a value of NUMBER type and DECFLOAT type, the result is a DECFLOAT value.
Use of the DECFLOAT type might cause storage consumption to increase.

Drivers and driver versions that support the DECFLOAT data type¶

The following Snowflake drivers and driver versions support the DECFLOAT data type. You might need to update your drivers to the versions that support DECFLOAT:

Driver	Minimum supported version	Notes
Snowflake Connector for Python	3.14.1	pandas DataFrames don’t support the DECFLOAT type.
ODBC	3.12.0	None.
JDBC	3.27.0	None.
Go Snowflake Driver	1.17.0	None.
SQL API	2.0.0	None.

Unsupported drivers treat DECFLOAT values as TEXT values. For some drivers, a driver parameter must be set to map the DECFLOAT type to a language-native type. For more information, see Drivers.

Limitations for the DECFLOAT data type¶

The following limitations apply to the DECFLOAT type:

DECFLOAT values can’t be stored in VARIANT, OBJECT, or ARRAY values. To cast a DECFLOAT value to a VARIANT value, you can first cast it to a VARCHAR value, and then cast it to a VARIANT value.
DECFLOAT values aren’t supported in the following types of tables:
- Tables in external formats, such as Iceberg
- Hybrid tables
The DECFLOAT data type isn’t supported in Snowflake Scripting stored procedures. However, it is supported in Snowflake Scripting user-defined functions (UDFs).
The DECFLOAT data type isn’t supported in stored procedures or UDFs written in a language other than SQL, such as Python or Java.
The DECFLOAT data type isn’t supported in Snowpark.
Snowsight has limited support for the DECFLOAT data type.
The following features don’t support the DECFLOAT data type:
The NUMBER and FLOAT types might provide better performance than the DECFLOAT type.

Examples for the DECFLOAT data type¶

The following examples use the DECFLOAT data type:

Show the differences between DECFLOAT and FLOAT
Use DECFLOAT values with aggregate functions

Show the differences between DECFLOAT and FLOAT¶

The following example shows the differences between the DECFLOAT and FLOAT data types:

Create a table with a DECFLOAT column and a FLOAT column, and then insert the same values for both types into the table:

CREATE OR REPLACE TABLE decfloat_sample (
  id INT,
  decfloat_val DECFLOAT,
  float_val FLOAT);

INSERT INTO decfloat_sample VALUES
  (
    1,
    DECFLOAT '123e7000',
    FLOAT '123e7000'
  ),
  (
    2,
    12345678901234567890123456789::DECFLOAT,
    12345678901234567890123456789::FLOAT
  ),
  (
    3,
    '-4.2e-5432'::DECFLOAT,
    '-4.2e-5432'::FLOAT
  ),
  (
    4,
    '1.00000000000000000000000000000000000014'::DECFLOAT,
    '1.00000000000000000000000000000000000014'::FLOAT
  ),
  (
    5,
    '1.00000000000000000000000000000000000015'::DECFLOAT,
    '1.00000000000000000000000000000000000015'::FLOAT
  );

Copy

The statement inserts DECFLOAT values in the following ways:

The first value is inserted by using the DECFLOAT literal.
The second value is inserted by casting an INTEGER value to a DECFLOAT value.
The third, fourth, and fifth values are inserted by casting a VARCHAR value to a DECFLOAT value.

To show the types, describe the table by using the DESC TABLE command.

The precision wasn’t specified in the table definition for either column, but the output shows that the DECFLOAT data type supports up to 38 significant digits of precision:

DESC TABLE decfloat_sample;

Copy

+--------------+--------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------+
| name         | type         | kind   | null? | default | primary key | unique key | check | expression | comment | policy name | privacy domain |
|--------------+--------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------|
| ID           | NUMBER(38,0) | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| DECFLOAT_VAL | DECFLOAT(38) | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
| FLOAT_VAL    | FLOAT        | COLUMN | Y     | NULL    | N           | N          | NULL  | NULL       | NULL    | NULL        | NULL           |
+--------------+--------------+--------+-------+---------+-------------+------------+-------+------------+---------+-------------+----------------+

To show the differences in the values, query the table by using the SELECT statement:
```
SELECT * FROM decfloat_sample;
```
Copy
```
+----+-----------------------------------------+------------------------+
| ID | DECFLOAT_VAL                            |              FLOAT_VAL |
|----+-----------------------------------------+------------------------|
|  1 | 1.23e7002                               | inf                    |
|  2 | 12345678901234567890123456789           |   1.23456789012346e+28 |
|  3 | -4.2e-5432                              |  -0                    |
|  4 | 1.0000000000000000000000000000000000001 |   1                    |
|  5 | 1.0000000000000000000000000000000000002 |   1                    |
+----+-----------------------------------------+------------------------+
```
The output shows the following differences:
- The first row shows that the DECFLOAT type supports a wider range of values than the FLOAT type. The DECFLOAT value is very large (1.23e7002). The FLOAT value is inf, which means that the value is larger than any value that the FLOAT type can represent.
- The second row shows that the DECFLOAT type retains the specified value exactly. The FLOAT value is an approximation that is stored in scientific notation.
- The third row shows that the DECFLOAT type supports very small values (-4.2e-5432). The FLOAT value is approximated to -0.
- The fourth and fifth rows show that the DECFLOAT type supports up to 38 digits of precision and uses rounding rules for values beyond the limit. The FLOAT value is approximated to 1 in both rows.

Use DECFLOAT values with aggregate functions¶

The following example uses DECFLOAT values with aggregate functions:

Create a table, and then insert DECFLOAT values into the table:

CREATE OR REPLACE TABLE decfloat_agg_sample (decfloat_val DECFLOAT);

INSERT INTO decfloat_agg_sample VALUES
  (DECFLOAT '1e1000'),
  (DECFLOAT '-2.47e999'),
  (DECFLOAT '22e-75');

Copy

Query the table by using some aggregate functions:

SELECT SUM(decfloat_val),
       AVG(decfloat_val),
       MAX(decfloat_val),
       MIN(decfloat_val)
  FROM decfloat_agg_sample;

Copy

+-------------------+-------------------+-------------------+-------------------+
| SUM(DECFLOAT_VAL) | AVG(DECFLOAT_VAL) | MAX(DECFLOAT_VAL) | MIN(DECFLOAT_VAL) |
|-------------------+-------------------+-------------------+-------------------|
| 7.53e999          | 2.51e999          | 1e1000            | -2.47e999         |
+-------------------+-------------------+-------------------+-------------------+

Constantes numéricas¶

The term constants — also known as literals — refers to fixed data values. The following formats are supported for numeric constants:

[+-][digits][.digits][e[+-]digits]

Onde:

+ ou - indica um valor positivo ou negativo. O padrão é positivo.
digits é um ou mais dígitos de 0 a 9.
e (ou E) indica um expoente em notação científica. Pelo menos um dígito deve seguir o marcador do expoente, se presente.

Os números a seguir são exemplos de constantes numéricas aceitas:

15
+1.34
0.2
15e-03
1.234E2
1.234E+2
-1