Guidance Needed: Table Field Expansion, Licensing, Performance, and Data Model Design Best Practices

[ashrotriya]

Hello ServiceNow Community,

I’m reaching out for advice and best practices regarding a scenario we’re facing with one of our tables. I’d appreciate input from both the support team and community experts.

Background

• We currently have a table with 103 fields already defined.
• Due to evolving business requirements, we anticipate the need to add even more fields.
• To accommodate this, we have started creating table extensions.
• There are related tables (let’s call them Table1 and Table2) that represent the same record in different contexts.

Questions and Concerns

1. Licensing Impact

• Will adding more fields or creating extensions to the current table have any impact on our ServiceNow licensing?
• Are there any field or table limits that could trigger additional licensing costs or restrictions?

2. Performance Considerations

• What are the potential performance impacts of having a table with a large number of fields (over 100, possibly more)?
• Are there best practices or thresholds we should be aware of to avoid performance degradation?
• Does the use of table extensions help or hinder performance in this scenario?

3. Data Model Design

• Given that Table1 and Table2 represent the same record, is it advisable to bring fields from these tables into our main table?
• Would it be better to reference these tables instead of duplicating fields?
• What is the recommended approach for designing a scalable and maintainable data model in this situation?

4. General Best Practices

• Are there any ServiceNow-recommended guidelines for managing tables with a large number of fields?
• Should we consider normalization or other data modeling techniques to optimize our design?

Summary of What We’re Looking For

• Licensing implications of expanding fields and using extensions
• Performance best practices for large tables
• Data model design recommendations for handling related tables and shared records
• General advice on maintaining scalability and maintainability

Any insights, documentation references, or real-world experiences would be greatly appreciated!

Thank you in advance for your support and guidance.

[Dr Atul G- LNG]

Hi @ashrotriya 

Background

• We currently have a table with 103 fields already defined.
• Due to evolving business requirements, we anticipate the need to add even more fields.
• To accommodate this, we have started creating table extensions.
• There are related tables (let’s call them Table1 and Table2) that represent the same record in different contexts.

Atul: While adding custom fields is generally not recommended as a best practice, it may be necessary depending on the business requirements and the criticality of capturing specific data in ServiceNow. The choice between extending an existing table or creating a new custom table should be driven by the use case, data structure, and maintainability considerations. For detailed guidance and best practices, please refer to this article.

https://www.servicenow.com/community/s/cgfwn76974/attachments/cgfwn76974/developer-forum/292935/4/Cu...

 Performance Considerations

• What are the potential performance impacts of having a table with a large number of fields (over 100, possibly more)?
• Are there best practices or thresholds we should be aware of to avoid performance degradation?
• Does the use of table extensions help or hinder performance in this scenario?

Atul: For example, in tables like Change or CMDB Computer where more than 100 fields exist, performance impact depends on how the fields are used. If all fields are added to the form, it can affect performance, especially depending on the field types. Fields like String, Reference, or Choice can have different performance impacts, and adding too many fields to the form may slow down load times and overall system responsiveness.