Do You Include “created_at” and “last_update_at” Fields in All Your Tables/Entities?

2 responses to “Do you have “created_at” and “last_update_at” fields on all your tables/entities? Yes? No? Why? Is it good / bad practice?”

1. When designing a database schema, the inclusion of metadata fields such as created_at and last_updated_at is a common consideration. These fields serve as audit trails, offering insights into when data entries were created and last modified. Let’s explore whether it’s advisable to incorporate these fields in all tables and delve into both the advantages and disadvantages of doing so.

   Universal Inclusion: Yes or No?

   Arguments for Inclusion

   1. Audit Trail: Having created_at and last_updated_at fields provides a clear record of when data was added and last modified. This is essential for debugging, compliance, and data analysis.

   2. Data Integrity and Consistency: Tracking changes over time can help ensure data integrity. For dynamic data where records frequently change or interact with business processes, these timestamps can be crucial.

   3. Historical Analysis: Time-based fields allow for temporal queries, helping businesses understand trends and changes over time.

   4. Allows for Soft Deletes: If you’re implementing soft deletes, these timestamps are often used in conjunction with a deleted_at field to manage record lifecycles effectively.

   Arguments Against Universal Inclusion

   1. Storage Overhead: While minimal, each additional field increases storage requirements. For vast datasets, even minor increases can accumulate into significant overhead.

   2. Complexity: Maintaining these fields requires additional effort in terms of logic and database triggers, which might not be necessary for simpler applications.

   3. Relevance: Not all tables require temporal tracking. For static tables, such as a table of states in a country, these fields may not add meaningful value. If a table’s data seldom changes and does not require historical context, including timestamps may not be necessary.

   Consideration for Static Tables

   For relatively stationary tables like a “state” table (listing states within a country), the necessity of these fields diminishes:

   • Stability: Geographic and political entities, once established, rarely change. As such, the created_at and last_updated_at fields might not provide substantial ongoing insight.
   • Low Change Frequency: The maintenance burden associated with continuously updated timestamps is not justified for datasets where change is infrequent or nonexistent.

   Good Practice or Bad Practice?

   Good Practice Scenarios

   • Dynamic and Transactional Data Sets: For tables that are frequently updated or used in transactions (e.g., orders, user profiles), incorporating timestamp fields is generally considered best

   Reply

2. Great discussion! Including `created_at` and `last_update_at` fields can serve as a useful audit trail, which can be crucial for debugging and understanding data changes over time, even in seemingly static tables like a State table.

   One of the key advantages is supporting data integrity and compliance. For example, if you ever need to track down when data was first added or when it was last modified, having these timestamps can save significant time.

   That said, it’s essential to weigh the benefits against potential drawbacks, such as added storage costs and complexity in querying. For tables that are indeed very static, one might consider whether the overhead is justified. An interesting compromise could be to implement these fields selectively or use them primarily for entities that are more dynamic.

   Ultimately, the decision should align with your application’s requirements and expected data lifecycle. Would love to hear others’ experiences with this—have you found unexpected benefits or challenges by tracking these timestamps in your projects?

   Reply