What are some best practices for naming and documenting snowflake schema tables and columns?

1 Use consistent and descriptive naming conventions

One of the first steps to design a snowflake schema is to choose a naming convention for your tables and columns. A naming convention is a set of rules or guidelines that help you identify the purpose, structure, and relationship of your data elements. A good naming convention should be consistent, descriptive, and easy to understand. For example, you can use prefixes or suffixes to indicate the type of table (dimension, fact, lookup, etc.), the level of granularity (day, month, year, etc.), or the source of data (sales, inventory, etc.). You can also use camel case, underscores, or hyphens to separate words and make them more readable. Avoid using spaces, special characters, or reserved keywords that might cause errors or confusion.

2 Document the metadata and business rules

Another important aspect of designing a snowflake schema is to document the metadata and business rules of your tables and columns. Metadata is the information that describes the data, such as the name, definition, data type, format, length, constraints, and dependencies of each element. Business rules are the logic or criteria that govern how the data is derived, transformed, validated, or aggregated. Documenting the metadata and business rules helps you maintain the quality, consistency, and accuracy of your data warehouse. It also helps you communicate the meaning and context of your data to other users or stakeholders. You can use tools such as data dictionaries, data catalogs, or data lineage diagrams to document your metadata and business rules.

3 Use surrogate keys and foreign keys

A key is a column or a set of columns that uniquely identifies a row in a table. A surrogate key is a key that is generated by the system and has no meaning or relation to the data. A foreign key is a key that references another key in a different table. Using surrogate keys and foreign keys is a best practice for naming and documenting snowflake schema tables and columns because it simplifies the data loading, integration, and querying processes. Surrogate keys make it easier to load data from different sources without worrying about conflicts or duplicates. Foreign keys make it easier to join tables and enforce referential integrity. You can use numeric or alphanumeric values for your surrogate keys and foreign keys, and document their origin and destination in your metadata.

4 Use meaningful aliases and labels

When you query your snowflake schema tables and columns, you might want to use aliases and labels to make your results more user-friendly and understandable. An alias is a temporary name that you assign to a table or a column in a query. A label is a permanent name that you assign to a table or a column in a view or a report. Using meaningful aliases and labels is a best practice for naming and documenting snowflake schema tables and columns because it helps you avoid confusion or ambiguity when you work with multiple tables or columns with similar or identical names. For example, you can use aliases to differentiate between the same column name in different tables, such as sales.amount and inventory.amount. You can also use labels to display the column name in a more readable or descriptive way, such as Total Sales or Inventory Value.

5 Use comments and annotations

Comments and annotations are another way to name and document your snowflake schema tables and columns. Comments are remarks or notes that you add to your code or script to explain or clarify something. Annotations are attributes or properties that you add to your tables or columns to provide additional information or functionality. Using comments and annotations is a best practice for naming and documenting snowflake schema tables and columns because it helps you document the logic, assumptions, or decisions behind your code or design. For example, you can use comments to explain why you used a certain formula, function, or condition in your query. You can also use annotations to specify the format, security, or access level of your tables or columns.

6 Follow the naming and documenting standards

The last but not least best practice for naming and documenting snowflake schema tables and columns is to follow the naming and documenting standards of your organization, project, or industry. Standards are the agreed-upon rules or norms that ensure the consistency, quality, and compatibility of your data warehousing solutions. Following the naming and documenting standards is a best practice for naming and documenting snowflake schema tables and columns because it helps you avoid errors, conflicts, or misunderstandings when you share or integrate your data with other systems or users. For example, you can follow the standards for naming conventions, metadata formats, documentation tools, or code styles that are established by your organization, project, or industry.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?