Differential privacy SQL reference¶

This topic provides the following information:

  • A reference for the SQL functions that are unique to differential privacy.

  • A list of the Snowflake data types, operators, query syntax, and functions that are supported by differential privacy.

Differential privacy functions¶

The following functions are unique to differential privacy.

Function

Description

DP_INTERVAL_LOW

Returns the lower bound of the noise interval.

DP_INTERVAL_HIGH

Returns the upper bound of the noise interval.

Data types¶

The following data types are supported.

Data type

Notes

BOOLEAN

CHAR, CHARACTER

DATE

DATETIME

DECIMAL, NUMERIC

DOUBLE, DOUBLE PRECISION, REAL

FLOAT, FLOAT4, FLOAT8

INT, INTEGER , BIGINT, SMALLINT, TINYINT, BYTEINT

NUMBER

STRING

TEXT

TIME

TIMESTAMP, TIMESTAMP_NTZ

Time data types with time zones are not supported. Use TIMESTAMP or TIMESTAMP_NTZ.

VARCHAR

Query syntax¶

The following elements of the Snowflake query syntax are supported.

Syntax

Notes

SELECT

SELECT ALL

FROM

INNER JOIN ON

See Supported joins.

INNER JOIN USING

See Supported joins.

LEFT OUTER JOIN ON

See Supported joins.

LEFT OUTER JOIN USING

See Supported joins.

RIGHT OUTER JOIN ON

See Supported joins.

RIGHT OUTER JOIN USING

See Supported joins.

FULL OUTER JOIN ON

See Supported joins.

FULL OUTER JOIN USING

See Supported joins.

NATURAL JOIN

See Supported joins.

WHERE

GROUP BY

Aliases are not supported in the GROUP BY clause. For example, GROUP BY col_a AS column_a is not supported.

Limitations on query syntax

Quoted identifiers (for example, column, table, schema and database names) are not supported.

Operators¶

Arithmetic operators¶

The following arithmetic operators are supported.

Operator

Notes

- (unary)

-

+ (unary)

Does not work with strings.

+

*

/

%

Comparison operators¶

The following comparison operators are supported.

Operator

Notes

=

!=

<

>

<=

>=

Logical operators¶

The following logical operators are supported.

Operator

Notes

AND

NOT

OR

Set operators¶

The following set operators are supported.

Operator

Notes

UNION [ ALL ]

Subquery operators¶

Subquery operators are not supported.

Functions¶

Aggregate functions¶

The following aggregate functions are supported.

Function

Notes

ANY_VALUE

Supported only as an aggregate for a subquery with a GROUP BY clause.

COUNT

COUNT DISTINCT

Bitwise expression functions¶

Bitwise expression functions are not supported.

Conditional expression functions¶

The following conditional expression functions are supported.

Function

Notes

[ NOT ] IN

CASE

COALESCE

DECODE

EQUAL_NULL

GREATEST

IFF

IS [NOT] NULL

LEAST

Context functions¶

Context functions are not supported.

Conversion functions¶

The following conversion functions are supported.

Function

Notes

CAST, ::

Columns must be explicitly non-null to be casted. To do this, filter out nulls before casting.

Casting other data types to STRING is not supported.

TO_BOOLEAN

TO_CHAR , TO_VARCHAR

TO_DECIMAL , TO_NUMBER , TO_NUMERIC

TO_DOUBLE

TRY_CAST

TRY_TO_BOOLEAN

TRY_TO_DECIMAL, TRY_TO_NUMBER, TRY_TO_NUMERIC

TRY_TO_DOUBLE

Data generation functions¶

Data generation functions are not supported.

Data metric functions¶

Data metric functions are not supported. User-defined DMFs are also not supported.

Date & time functions¶

The following date & time functions are supported.

Function

Notes

DATE_PART

The following date and time parts are not supported: dayofweek, week, yearofweek, nanosecond, epoch_*, and timezone_*.

DAYNAME

EXTRACT

The following date and time parts are not supported: dayofweek, week, yearofweek, nanosecond, epoch_*, and timezone_*.

HOUR

LAST_DAY

MINUTE

SECOND

TRUNC

YEAR* / DAY* / WEEK* / MONTH / QUARTER

Encryption functions¶

Encryption functions are not supported.

File functions¶

File functions are not supported.

Geospatial functions¶

Geospatial functions are not supported.

Hash functions¶

Hash functions are not supported.

Metadata functions¶

Metadata functions are not supported.

Numeric functions¶

The following numeric functions are supported.

Function

Notes

ABS

CEIL

FLOOR

MOD

SIGN

Regular expression functions¶

Regular expression functions are not supported.

Semi-structured and structured data functions¶

Semi-structured and structured data functions are not supported.

String and binary functions¶

The following string & binary functions are supported.

Function

Notes

CONTAINS

LENGTH , LEN

LOWER

POSITION

UPPER

System functions¶

System functions are not supported.

Table functions¶

Table functions are not supported.