How to resolve duplicate Oracle UUIDs?

In Oracle, UUIDs are generated using the SYS_GUID function. This function is created internally by Oracle, ensuring uniqueness globally. However, because UUID generation is based on timestamps and other information, there is a very rare chance of duplicate UUIDs occurring.

If duplicate UUIDs occur in Oracle, the following measures can be taken to resolve the issue:

1. Using different UUID generation algorithms: If you are using the SYS_GUID function to generate UUIDs, you may want to consider using other algorithms such as UUID version 4 (random generation) or UUID version 5 (based on namespace and name). These algorithms can be implemented at the application layer to ensure the uniqueness of the generated UUIDs.
2. Increasing the length of UUID: One option is to consider increasing the length of UUID so that the generated UUIDs are more unique. In Oracle, the length of UUID generated by SYS_GUID is 16 bytes. It is possible to generate longer UUIDs, such as 32 bytes or more, at the application layer to improve uniqueness.
3. Introducing alternative identifiers: it may be beneficial to introduce additional unique identifiers, such as auto-increment primary keys in databases or business-specific identifiers, as supplemental information to UUIDs to ensure uniqueness.
4. Check the method of generating UUID: Review the way in which UUIDs are being generated to ensure that there are no issues such as using the same timestamp across multiple nodes, which could result in duplicate UUIDs. Make sure that the method of generating UUIDs is correct.

In general, it is extremely rare to encounter duplicate UUIDs in Oracle, and this issue can be resolved using the above measures. It’s important to note that UUIDs are designed to be unique globally, so duplicates are typically not expected. If duplicate UUIDs do arise, it is recommended to carefully examine the method and scenario used for generating the UUIDs, and take appropriate measures based on the specific circumstances.