Built-in functions
Aggregate Functions
Aggregate functions compute a single result value from a set of input values. (Redshift SQL Language Reference Aggregate Functions).
ANY_VALUE ( [ DISTINCT | ALL ] expression )
ANY_VALUE ( [ DISTINCT ]expression )
Notes: Snowflake supports the grammar, though ALL is disallowed. DISTINCT has no effect in either.
AVG ( [ DISTINCT | ALL ] expression )
AVG ( [ DISTINCT ] expression)
Notes: Redshift and Snowflake may show different precision/decimals due to data type rounding/formatting.
Notes: Redshift's DISTINCT ignores trailing spaces ('a ' = 'a'); Snowflake's does not. (See SSC-FDM-PG0013).
Notes: Snowflake does not allow the use of date types, while Redshift does. (See SSC-FDM-PG0013).
STDDEV/STDDEV_SAMP ( [ DISTINCT | ALL ] expression)
STDDEV_POP ( [ DISTINCT | ALL ] expression)
STDDEV/STDDEV_SAMP ( [ DISTINCT ] expression)
STDDEV_POP ( [ DISTINCT ] expression)
Notes: Snowflake supports all the grammar, though ALL is disallowed.
VARIANCE/VAR_SAMP ( [ DISTINCT | ALL ] expression)
VAR_POP ( [ DISTINCT | ALL ] expression)
VARIANCE/VAR_SAMP ( [ DISTINCT ] expression)
VAR_POP ( [ DISTINCT ] expression)
Notes: Snowflake supports all the grammar, though ALL is disallowed.
Array Functions
Creates an array of the SUPER data type. (Redshift SQL Language Reference Array Functions).
ARRAY ( [ expr1 ] [ , expr2 [ , ... ] ] )
( [ <expr1> ] [ , <expr2> [ , ... ] ] )
ARRAY_CONCAT ( super_expr1, super_expr2 )
ARRAY_CAT ( <array1> , <array2> )
( super_expr1,super_expr2,.. )
ARRAY_FLATTEN ( <array> )
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
GET_ARRAY_LENGTH ( super_expr )
ARRAY_SIZE ( <array> | <variant>)
SPLIT_TO_ARRAY ( string,delimiter )
SPLIT (<string>, <separator>)
Notes: Redshift allows missing delimiters; Snowflake requires them, defaulting to comma
SUBARRAY ( super_expr, start_position, length )
ARRAY_SLICE ( <array> , <from> , <to> )
Notes: Function names and the second argument differ; adjust arguments for equivalence.
Conditional expressions
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
GREATEST ( value [, ...] )
GREATEST_IGNORE_NULLS ( <expr1> [, <expr2> ... ] )
LEAST ( value [, ...] )
LEAST_IGNORE_NULLS ( <expr1> [, <expr2> ... ])
Data type formatting functions
Data type formatting functions provide an easy way to convert values from one data type to another. For each of these functions, the first argument is always the value to be formatted and the second argument contains the template for the new format. (Redshift SQL Language Reference Data type formatting functions).
Notes: Snowflake's support for this function is partial (see SSC-EWI-PG0005).
Notes: Snowflake's TO_DATE
fails on invalid dates like '20010631' (June has 30 days), unlike Redshift's lenient TO_DATE
. Use TRY_TO_DATE
in Snowflake to handle these cases by returning NULL. (see SSC-FDM-RS0004, SSC-EWI-PG0005, SSC-FDM-0032).
Date and time functions
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
CONVERT_TIMEZONE ( <source_tz> , <target_tz> , <source_timestamp_ntz> )
CONVERT_TIMEZONE ( <target_tz> , <source_timestamp> )
Notes: Redshift defaults to UTC; the Snowflake function requires explicit UTC specification. Therefore, it will be added as the target timezone.
DATEADD/DATE_ADD ( datepart, interval, {date | time | timetz | timestamp} )
DATE_ADD ( <date_or_time_part>, <value>, <date_or_time_expr> )
Notes: Invalid date part formats are translated to Snowflake-compatible formats.
Notes: Invalid date part formats are translated to Snowflake-compatible formats.
Notes: this function is partially supported by Snowflake. (See SSC-EWI-PGOOO5).
DATE_PART_YEAR (date)
YEAR ( <date_or_timestamp_expr> )
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
Notes: Invalid date part formats are translated to Snowflake-compatible formats.
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
Hash Functions
A hash function is a mathematical function that converts a numerical input value into another value. (Redshift SQL Language Reference Hash functions).
JSON Functions
Notes:
Redshift treats newline, tab, and carriage return characters literally; Snowflake interprets them.
A JSON literal and dot-separated path are required to access nested objects in the Snowflake function.
Paths with spaces in variables must be quoted.
Math functions
String functions
String functions process and manipulate character strings or expressions that evaluate to character strings. (Redshift SQL Language Reference String functions).
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
QUOTE_IDENT (string)
CONCAT ('"', string, '"')
Notes: This function includes a parameters
argument that enables the user to interpret the pattern using the Perl Compatible Regular Expression (PCRE) dialect, represented by the p
value, this is removed to avoid any issues. (See SSC-EWI-0009, SC-FDM-0032, SSC-FDM- PG0011).
Notes: Certain special characters, the results may vary between platforms (See SSC-FDM-PG0013).
Notes: Snowflake and Redshift handle SPLIT_PART differently with case-insensitive collations.
Notes: Snowflake partially supports this function. Redshift's SUBSTRING
, with a non-positive start_position
, calculates start_position + number_characters
(returning '' if the result is non-positive). Snowflake's behavior differs. (See SSC-EWI-RS0006).
Notes: Redshift uses keywords (BOTH, LEADING, TRAILING) for trim; Snowflake uses TRIM, LTRIM, RTRIM.
SUPER type information functions
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
Window functions
Notes: ORDER BY is mandatory in Snowflake; missing clauses are replaced with ORDER BY 1
.
Notes: Snowflake needs ORDER BY; missing clauses get ORDER BY <expr>.
Notes: Snowflake needs ORDER BY; missing clauses get ORDER BY <expr>
.
Notes: Redshift allows constant or expression offsets; Snowflake allows only constant offsets.
Notes: Redshift's DISTINCT ignores trailing spaces ('a ' = 'a'); Snowflake's does not. (See SSC-FDM-PG0013).
Notes: Snowflake does not allow the use of date types, while Redshift does. (See SSC-FDM-PG0013).
Notes: ORDER BY is mandatory in Snowflake; missing clauses are replaced with ORDER BY 1
.
Notes: ORDER BY is mandatory in Snowflake; missing clauses are replaced with ORDER BY 1
. (See SSC-FDM-PG0013).
Notes: ORDER BY is mandatory in Snowflake; missing clauses are replaced with ORDER BY 1
.
Notes: Rounding varies between platforms.
Notes: the results may vary between platforms (See SSC-FDM-PG0013).
Notes: ORDER BY is mandatory in Snowflake; missing clauses are replaced with ORDER BY 1
.
STDDEV_SAMP | STDDEV | STDDEV_POP
( [ ALL ] expression )
OVER ( [ PARTITION BY expr_list ]
[ ORDER BY order_list frame_clause ] )
STDDEV/STDDEV_SAMP /STDDEV_POP
( [ DISTINCT ] expr1) OVER ( [ PARTITION BY expr2 ] [ ORDER BY expr3 [ ASC | DESC ] [ <window_frame> ] ] )
Notes: Snowflake supports all the grammar, though ALL is disallowed.
( [ ALL ] expression )
OVER ( [ PARTITION BY expr_list ]
[ ORDER BY order_list frame_clause ] )
( [ DISTINCT ] expr1) OVER ( [ PARTITION BY expr2 ] [ ORDER BY expr3 [ ASC | DESC ] [ <window_frame> ] ] )
Notes: Snowflake supports all the grammar, though ALL is disallowed.
Known Issues
For more information about quoted identifiers in functions, click here.
Related EWIs
SSC-EWI-PG0005: Date or time format is not supported in Snowflake.
SSC-FDM-0032: Parameter is not a literal value, transformation could not be fully applied
SSC-FDM-PG0013: Function syntactically supported by Snowflake but may have functional differences.
SSC-FDM-RS0004: Invalid dates will cause errors in Snowflake.
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