GUIDs (Globally Unique Identifiers) have long been a standard in the .NET ecosystem, offering a method of generating unique identifiers with an exceptionally low chance of collision across different systems. These identifiers are random and not sequential, ensuring that they are not predictable, making them suitable for a variety of use cases in distributed systems and databases.
A typical GUID has the following format: 123e4567-e89b-12d3-a456-426614174000.
While GUIDs have served the technology world well, they do come with certain limitations. A new contender, ULID (Universally Unique Lexicographically Sortable Identifier), has emerged to address some of these challenges. ULIDs aim to retain the key benefits of GUIDs—uniqueness and low collision probability—while offering advantages like lexicographical sorting, which can improve database performance and make identifiers more human-readable.
Now before I show the advantage of using ULID vs GUID I want to show an example on how these unique identifiers can optimize your database insertions vs the normal database generated indentifiers.
Here I Implemented a repository pattern
And my scenario is to insert on multiple tables the Product and Asset that expects to return a string.
A major challenge when not using a generated unique identifier is that we often need to generate the ID first before we can use it. This typically means calling SaveChanges to trigger the generation of the ID, which adds an unnecessary step in the process.
Unique identifiers, such as GUIDs and ULIDs, solve this problem by allowing us to generate and assign the ID upfront. This eliminates the need for additional database roundtrips and simplifies the workflow, as we can assign a unique ID immediately without waiting for the database to generate it.
On my case I’m handing the generation on my BaseEntity.
Now moving on the creation of asset on my API that returns the generated ULID.
Another major advantage of ULID beside it’s a unique identifier is that it includes timestamp for the generated IDs.
Why ULID Over GUID?
While GUIDs are still widely used, I am leaning toward using ULIDs in my project for several reasons:
Timestamp embedded: The ability to include the generation timestamp in the identifier is incredibly useful for sorting and tracking.
Performance benefits: ULIDs are lexicographically sortable, which can lead to better indexing performance in databases.
Consistency: ULIDs help maintain a consistent pattern for unique identifiers across distributed systems without the need for database roundtrips.
Since I'm using .NET 8 for this project, I’ve opted to use a NuGet package for ULID, as it’s not built-in as a standard .NET feature (yet).
Conclusion
In summary, both GUIDs and ULIDs serve the same purpose of providing unique identifiers. However, ULIDs bring additional benefits, such as:
Sortability (useful for efficient indexing)
Timestamp inclusion (providing more context to the identifier)
Compact and efficient storage (like GUIDs but with added flexibility)
Given these advantages, I plan to adopt ULIDs in my project, particularly when I need to ensure uniqueness without sacrificing performance. Whether you're handling distributed systems or simply need a more efficient way to generate unique identifiers, ULIDs are worth considering over traditional GUIDs.