Code Conversion - Understanding Converted Code¶

Definitions¶

Code Conversion produces messages in the converted code that highlight areas requiring additional work to ensure the code functions correctly in Snowflake.

EWI (Errors, Warnings and Issues)¶

When a code segment cannot be completely converted, an Error, Warning, and Issue (EWI) message is generated. Each EWI negatively affects the conversion rate of a code unit. Here are the common reasons why code might not be fully converted:

• The required conversion rule has not been created yet
• Required dependent code is missing for the conversion rule to work
• An equivalent statement is not available in Snowflake, or a User-Defined Function (UDF) has not been developed to provide the needed functionality

A !!!RESOLVE EWI!!! marker is added before each EWI (Error, Warning, and Issue) message. This marker causes compilation to fail, ensuring that developers address these issues before deploying the converted code.

The EWIs (Errors, Warnings, and Issues) are categorized into four severity levels based on the average effort required to fix the code:

• Low
• Medium
• High
• Critical

FDM (Functional Difference Messages)¶

When converting code from legacy platforms (such as Teradata, Oracle, or SQL Server) to Snowflake, it’s important to understand that these systems have different features and capabilities. Due to these differences, automatic conversion may not provide complete functional equivalence, and manual intervention is often necessary to address these gaps.

A Functional Difference Message (FDM) appears when code is successfully converted that compiles correctly but may not function exactly like the original source code. This can happen when Snowflake doesn’t support certain features from the source platform. Resolving these differences often requires business decisions or architectural changes beyond simple code conversion. Since FDMs are added as comments to working code, they don’t affect the code’s ability to compile.

PRF (Performance Review)¶

These warning messages are added to the converted code to inform users that although the code has been correctly translated, it may not perform optimally in certain situations. To achieve the best performance in Snowflake, some code modifications may be necessary.

OOS (Out Of Scope)¶

Certain code units cannot be automatically converted. Specific top-level code units will be classified as out-of-scope for multiple reasons, such as:

• they are not relevant in Snowflake
• there is no comparable code unit in Snowflake
• the code unit definition is not readable (ex: encrypted)
• the code unit definition is in a not supported programming language (ex: java)

Lines of code of code units out of the conversion scope will not be used to calculate conversion rates, but they will be used to provide some information in the assessment documents. For example, a Database Link object In Oracle is considered out of scope, however, references made to this object are still counted.

The following is the list of Code Units per language considered out of the conversion scope.

Teradata out-of-conversion scope code units¶

• Triggers
• Grants
• Functions or procedures with unsupported language

Oracle out-of-conversion scope code units¶

• Triggers
• Grants
• DB Links
• Wrapped Objects
• Functions or procedures with unsupported languages

Transact SQL out-of-conversion scope code units¶

• Triggers
• Grants

Redshift out-of-conversion scope code units¶

• Grants

New Codes Format¶

We have updated the format of Error, Warning, and Issue (EWI) messages to be more user-friendly. The new format makes it easier to identify both the message type and the programming language it relates to. Below, we’ll explain these changes with examples.

General¶

General Errors, Warnings, and Issues (EWIs) that do not correspond to any supported programming language will no longer use the code 1000. Instead, these EWIs will be identified by the absence of a language-specific abbreviation.

Example¶

Teradata¶

Teradata Errors, Warnings, and Issues (EWIs) previously used codes starting with 2000. Now, these codes will begin with ‘TD’ followed by the numeric portion.

Example¶

Oracle¶

Oracle Errors, Warnings, and Issues (EWIs) previously used codes starting with 3000. Now, these codes will begin with ‘OR’ followed by the numeric portion of the code.

Example¶

SQL Server¶

SQL Server Errors, Warnings, and Issues (EWIs) codes have been updated. Previously, these codes started with 2000. Now, they begin with ‘TS’ followed by a numeric value.

Example¶

Changed Category To FDM¶

Changed Category To PRF¶

Deprecated EWIs¶