SnowConvert: PostgreSQL Issues¶

Note

Conversion Scope

SnowConvert for PostgreSQL currently supports assessment and translation for TABLES and VIEWS. Although SnowConvert can recognize other types of statements, they are not fully supported.

SSC-EWI-PG0001¶

Age is not supported on Snowflake

Severity¶

Medium

Description¶

This error is added because SnowConvert does not support the age() functionality.

Code Example¶

Input Code:¶

PostgreSQL¶ SELECT
   age(date1::date, date2::date)
FROM
   Table1;
Copy


Generated Code:¶

Snowflake¶ --** SSC-FDM-0007 - MISSING DEPENDENT OBJECTS "age", "Table1" **
SELECT
   !!!RESOLVE EWI!!! /*** SSC-EWI-PG0001 - AGE IS NOT SUPPORTED ON SNOWFLAKE. ***/!!!
   AGE(date1::date, date2::date)
FROM
   Table1;
Copy

Best Practices¶

The Datediff time function can solve some cases where the objective of the query is to obtain a specific range of values but this has to be handled manually for each scenario. For more information please refer to the Snowflake documentation about Datediff.
If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0002¶

Constraint index parameter not supported

Severity¶

Low

Description¶

The use of the following index parameters in constraints are not supported by Snowflake.

INCLUDE
WITH
USING INDEX TABLESPACE

Code Example¶

Input Code:¶

PostgreSQL¶

 CREATE TABLE Table1 (
    code        char(5),
    date_prod   date,
    CONSTRAINT production UNIQUE(date_prod) INCLUDE(code)
);

CREATE TABLE Table2 (
    name    varchar(40),
    UNIQUE(name) WITH (fillfactor=70)
);

CREATE TABLE Table3 (
    name    varchar(40),
    PRIMARY KEY(name) USING INDEX TABLESPACE tablespace_name
);

Copy

Generated Code:¶

Snowflake¶

 CREATE TABLE Table1 (
    code        char(5),
    date_prod   date,
    CONSTRAINT production UNIQUE(date_prod)
                                            !!!RESOLVE EWI!!! /*** SSC-EWI-PG0002 - INCLUDE PARAMETER NOT APPLICABLE. CONSTRAINT INDEX PARAMETERS ARE NOT SUPPORTED IN SNOWFLAKE. ***/!!! INCLUDE(code)
)
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "postgresql",  "convertedOn": "09/17/2024" }}';

CREATE TABLE Table2 (
    name    varchar(40),
    UNIQUE(name)
                 !!!RESOLVE EWI!!! /*** SSC-EWI-PG0002 - WITH PARAMETER NOT APPLICABLE. CONSTRAINT INDEX PARAMETERS ARE NOT SUPPORTED IN SNOWFLAKE. ***/!!! WITH (fillfactor=70)
)
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "postgresql",  "convertedOn": "09/17/2024" }}';

CREATE TABLE Table3 (
    name    varchar(40),
    PRIMARY KEY(name)
                      !!!RESOLVE EWI!!! /*** SSC-EWI-PG0002 - USING PARAMETER NOT APPLICABLE. CONSTRAINT INDEX PARAMETERS ARE NOT SUPPORTED IN SNOWFLAKE. ***/!!! USING INDEX TABLESPACE tablespace_name
)
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "postgresql",  "convertedOn": "09/17/2024" }}';

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0003¶

Inheritance not supported

Severity¶

Low

Description¶

Inheritance between tables is allowed in PostgreSQL, but Snowflake does not support it. For more information about inheritance in PostgreSQL click here.

Code Example¶

Input Code:¶

PostgreSQL¶

 ALTER TABLE Table1
ADD CONSTRAINT const3 UNIQUE (zip);

Copy

Generated Code:¶

Snowflake¶

 !!!RESOLVE EWI!!! /*** SSC-EWI-PG0003 - TABLE INHERITANCE IS NOT SUPPORTED IN SNOWFLAKE. ***/!!!
ALTER TABLE Table1
ADD CONSTRAINT const3 UNIQUE (zip);

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0004¶

Exclude constraint not supported

Severity¶

Medium

Description¶

The exclude constraint used in PostgreSQL is not supported by Snowflake.

Code Example¶

Input Code:¶

PostgreSQL¶

 CREATE TABLE Table1 (
    id      int,
    EXCLUDE USING gist (id WITH &&)
);

Copy

Generated Code:¶

Snowflake¶

 CREATE TABLE Table1 (
    id      int,
    !!!RESOLVE EWI!!! /*** SSC-EWI-PG0004 - EXCLUDE CONSTRAINT IS NOT SUPPORTED IN SNOWFLAKE. ***/!!!
    EXCLUDE USING gist (id WITH &&)
)
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "postgresql",  "convertedOn": "09/17/2024" }}';

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0006¶

Reference to a variable using the Label is not supported by Snowflake.

Severity¶

Medium

Description¶

This error is added when a FOR loop’s body references a variable using the label. Snowflake does not support referencing a variable using the qualified name.

Code Example¶

Input Code:¶

PostgreSQL¶

 CREATE OR REPLACE PROCEDURE procedure1(out result VARCHAR(100))
LANGUAGE plpgsql
AS $$
BEGIN
result := '<';
<<outer_loop>>
for i in 1..3 loop
  <<inner_loop>>
  for i in 4..6 loop
  result := result || '(' || outer_loop.i || ', ' || i || ')';
  end loop inner_loop;
end loop outer_loop;
result := result || '>';
END;
$$;

Copy

Generated Code:¶

Snowflake¶

 CREATE OR REPLACE PROCEDURE procedure1 (result VARCHAR(100))
RETURNS VARIANT
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "postgresql",  "convertedOn": "07/14/2025",  "domain": "no-domain-provided" }}'
AS $$
BEGIN
result := '<';
for i in 1 TO 3
                --** SSC-PRF-0008 - PERFORMANCE REVIEW - LOOP USAGE **
                loop
  for i in 4 TO 6
                  --** SSC-PRF-0008 - PERFORMANCE REVIEW - LOOP USAGE **
                  loop
  result := result || '(' ||
                             !!!RESOLVE EWI!!! /*** SSC-EWI-PG0006 - REFERENCE TO A VARIABLE USING THE LABEL IS NOT SUPPORTED BY SNOWFLAKE. ***/!!! outer_loop.i || ', ' || i || ')';
  end loop inner_loop;
end loop outer_loop;
result := result || '>';
RETURN OBJECT_CONSTRUCT('result', :result);
END;
$$;

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0007¶

Into clause in Dynamic SQL is not support in Snowflake

Severity¶

Low

Description¶

PostgreSQL Dynamic SQL allows the INTO clause to store query results in variables. Snowflake does not support this functionality. Therefore, the INTO clause will be flagged with an EWI’.

Code Example¶

Input Code:¶

PosgreSQL¶

 CREATE OR REPLACE PROCEDURE get_max_id(table_name VARCHAR, OUT max_id INTEGER)
AS $$
DECLARE
    sql_statement VARCHAR;
BEGIN
    sql_statement := 'SELECT MAX(id) FROM ' || table_name || ';';
    EXECUTE sql_statement INTO max_id;
END;
$$ LANGUAGE plpgsql;

Copy

Generated Code:¶

Snowflake¶

 CREATE OR REPLACE PROCEDURE get_max_id (table_name VARCHAR, max_id INTEGER)
RETURNS VARIANT
LANGUAGE SQL
COMMENT = '{ "origin": "sf_sc", "name": "snowconvert", "version": {  "major": 0,  "minor": 0,  "patch": "0" }, "attributes": {  "component": "postgresql",  "convertedOn": "07/02/2025",  "domain": "no-domain-provided" }}'
AS $$
DECLARE
    sql_statement VARCHAR;
BEGIN
    sql_statement := 'SELECT MAX(id) FROM ' || table_name || ';';
    EXECUTE IMMEDIATE sql_statement
                                    !!!RESOLVE EWI!!! /*** SSC-EWI-PG0007 - INTO CLAUSE IN DYNAMIC SQL IS NOT SUPPORTED IN SNOWFLAKE. ***/!!! INTO max_id;
    RETURN OBJECT_CONSTRUCT('max_id', :max_id);
END;
$$;

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0008¶

The use of interval within a to_char function is not compatible with Snowflake.

Severity¶

High

Description¶

The use of interval within the to_char to convert date/times data types into text is not supported in Snowflake.

Code Example¶

Input Code:¶

PostgreSQL¶

 SELECT to_char(interval '15h 2m 12s', 'HH24:MI:SS');

Copy

Generated Code:¶

Snowflake¶

 SELECT to_char(INTERVAL '15h, 2m, 12s', 'HH24:MI:SS') !!!RESOLVE EWI!!! /*** SSC-EWI-PG0008 - THE USE OF INTERVAL WITHIN TO_CHAR IS NOT SUPPORTED BY SNOWFLAKE. ***/!!!;

Copy

For more information please refer to

PostgreSQL to_char.
SnowFlake to_char.

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0009¶

Comment on ‘Type’ is not supported by Snowflake.

Severity¶

Low

Description¶

In the original code, there are various objects that can receive comments. However, in Snowflake, several of these objects do not exist, and thus, comments cannot be assigned to them. The code for handling these scenarios is commented out to prevent any potential errors.

Code Example¶

Input Code:¶

PostgreSql¶

 COMMENT ON RULE rule_name on TABLE_NAME IS 'this is a comment';

Copy

Generated Code:¶

Snowflake¶

 !!!RESOLVE EWI!!! /*** SSC-EWI-PG0009 - COMMENT ON 'RULE' IS NOT SUPPORTED BY SNOWFLAKE. ***/!!!
COMMENT ON RULE rule_name on TABLE_NAME IS 'this is a comment';

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0010¶

Create temporary sequence is not supported by Snowflake

Severity¶

Low

Description¶

When a temporary sequence is created in PostgreSQL, it is only created for the active session and is automatically deleted when you log out of the session. However, this functionality is not available in Snowflake, so it is generated as a normal sequence. When executed, a similar sequence name may already exist, which will cause an error for an existing object.

Code Example¶

Input code:¶

PostgreSQL¶

 CREATE TEMPORARY SEQUENCE sequence1;
CREATE TEMP SEQUENCE sequence2;

Copy

Generated Code:¶

Snowflake¶

 --** SSC-FDM-PG0009 - THE SEQUENCE NEXTVAL PROPERTY SNOWFLAKE DOES NOT GUARANTEE GENERATING SEQUENCE NUMBERS WITHOUT GAPS. **
CREATE TEMPORARY !!!RESOLVE EWI!!! /*** SSC-EWI-PG0010 - CREATE TEMPORARY SEQUENCE IS NOT SUPPORTED BY SNOWFLAKE. ***/!!! SEQUENCE sequence1;


--** SSC-FDM-PG0009 - THE SEQUENCE NEXTVAL PROPERTY SNOWFLAKE DOES NOT GUARANTEE GENERATING SEQUENCE NUMBERS WITHOUT GAPS. **
 CREATE TEMP !!!RESOLVE EWI!!! /*** SSC-EWI-PG0010 - CREATE TEMPORARY SEQUENCE IS NOT SUPPORTED BY SNOWFLAKE. ***/!!! SEQUENCE sequence2;

Copy

Best Practices¶

If you have a creation problem, you can try to rename the sequence to avoid collisions.
If you need more support, you can email us at snowconvert-support@snowflake.com.

SSC-EWI-PG0011¶

The sequence option ‘option_name’ is not supported by Snowflake.

Severity¶

Low

Description¶

Some options available in PostgreSQL for the sequence statement are not supported by Snowflake.

The unsupported options are:

Unlogged.
AS <data_type>.
MinValue.
MaxValue.
No MinValue.
No MaxValue.
Cache.
Cycle.
Owner By.

Code Example¶

Input code:¶

PostgreSQL¶

 CREATE UNLOGGED SEQUENCE sequence_name;

Copy

Generated Code:¶

Snowflake¶

 --** SSC-FDM-PG0009 - THE SEQUENCE NEXTVAL PROPERTY SNOWFLAKE DOES NOT GUARANTEE GENERATING SEQUENCE NUMBERS WITHOUT GAPS. **
CREATE UNLOGGED !!!RESOLVE EWI!!! /*** SSC-EWI-PG0011 - 'UNLOGGED' IS NOT SUPPORTED BY SNOWFLAKE. ***/!!! SEQUENCE sequence_name;

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0012¶

NOT VALID constraint option is not supported by Snowflake.

Description¶

The NOT VALID constraint option is used in the context of adding or altering a constraint to indicate that the constraint should be added or modified without checking the existing data for compliance with the constraint. This clause is not supported by Snowflake.

Code Example¶

Input Code:¶

PostgreSQL¶

 ALTER TABLE Table1 *
ADD CONSTRAINT const UNIQUE (zip) NOT VALID;

Copy

Generated Code:¶

Snowflake¶

 ALTER TABLE Table1
ADD CONSTRAINT const UNIQUE (zip)
                                  !!!RESOLVE EWI!!! /*** SSC-EWI-PG0012 - NOT VALID CONSTRAINT OPTION IS NOT SUPPORTED BY SNOWFLAKE. ***/!!! NOT VALID;

Copy

Best Practices¶

No additional user actions are required.
If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0014¶

Snowflake scripting cursors do not support fetch orientation

Severity¶

Medium

Description¶

In Snowflake, the FETCH cursor statement always fetches the next row in the cursor. When transforming the code, SnowConvert will transform cursor orientations that are equivalent to a FETCH NEXT as they are functionally equivalent in Snowflake, namely:

FETCH NEXT
FETCH FORWARD
FETCH RELATIVE 1
FETCH (no orientation specified)

Any other orientation is unsupported and the FETCH statement will be marked with this EWI to reflect that.

Code Example¶

Input Code:¶

PostgreSQL¶

 CREATE OR REPLACE PROCEDURE cursor_test()
AS $$
BEGIN
   FETCH FORWARD FROM cursor1 INTO my_var;
   FETCH FIRST FROM cursor1 INTO my_var;
   FETCH LAST FROM cursor1 INTO my_var;
END;
$$;

Copy

Generated Code:¶

Snowflake¶

 CREATE OR REPLACE PROCEDURE cursor_test ()
RETURNS VARCHAR
AS $$
BEGIN
   FETCH
   	cursor1 INTO my_var;
   !!!RESOLVE EWI!!! /*** SSC-EWI-PG0014 - SNOWFLAKE SCRIPTING CURSORS DO NOT SUPPORT FETCH ORIENTATION. ***/!!!
   FETCH FIRST FROM cursor1 INTO my_var;
   !!!RESOLVE EWI!!! /*** SSC-EWI-PG0014 - SNOWFLAKE SCRIPTING CURSORS DO NOT SUPPORT FETCH ORIENTATION. ***/!!!
   FETCH LAST FROM cursor1 INTO my_var;
END;
$$;

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0015¶

Fetch cursor without target variables is not supported in Snowflake

Severity¶

Medium

Description¶

In PostgreSQL, it is possible to use a FETCH statement without INTO to print on the console the values of fetched rows. However, Snowflake requires the FETCH statement to specify the INTO clause with the variables where the fetched row values are going to be stored.

Whenever a FETCH with no INTO is found in the code, SnowConvert will generate this EWI to notify the user that this type of FETCH is not supported.

Code Example¶

Input Code:¶

PostgreSQL¶

 FETCH PRIOR FROM cursor1;

Copy

Generated Code:¶

Snowflake¶

 !!!RESOLVE EWI!!! /*** SSC-EWI-PG0015 - FETCH CURSOR WITHOUT TARGET VARIABLES IS NOT SUPPORTED IN SNOWFLAKE ***/!!!
FETCH PRIOR FROM cursor1;

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com

SSC-EWI-PG0016¶

Bit String Type converted to Varchar Type

Severity¶

Low

Description¶

When migrating from PostgreSQL, be aware that its BIT String Types and related functions are not natively supported in Snowflake. These data types will be converted to Snowflake’s VARCHAR. This conversion means that any PostgreSQL queries or application logic that depend on bitwise operations on these columns will require significant modification to achieve the same functionality in Snowflake.

Code Example¶

Input Code:¶

PostgreSQL¶

 CREATE TABLE table1 (
   col1 bit(10)
);

Copy

Generated Code:¶

Snowflake¶

 CREATE TABLE table1 (
   col1 CHARACTER(10) !!!RESOLVE EWI!!! /*** SSC-EWI-PG0016 - BIT DATA TYPE CONVERTED TO CHARACTER ***/!!!
);

Copy

Best Practices¶

If you need more support, you can email us at snowconvert-support@snowflake.com