Can Datastore's AllocateIDs Function Generate Unique String Identifiers?

Datastore AllocateIDs Function and String Keys

Question: Can the AllocateIDs function in Datastore be used to generate unique string identifiers for entities?

Answer:

No, AllocateIDs generates integer identifiers (_numeric IDs_), not strings (_key names_). Assigning a string to an entity's numeric ID field is not a recommended practice. Doing so may lead to inconsistency and potential data loss.

Understanding Entity Identifiers in Datastore

Each entity in Datastore has a unique identifier, which can either be a string (_key name_) or an integer (_numeric ID_). These identifiers are distinct and cannot be used interchangeably.

AllocateIDs is used to allocate a range of unused numeric IDs that Datastore will not generate automatically. This ensures that you can safely use the allocated IDs for new entities without risk of collision.

String vs. Integer Identifiers

While strings may seem convenient for storing unique identifiers, using them for numeric IDs has several drawbacks:

• Lack of Consistency: Datastore does not guarantee the uniqueness of string _numeric IDs_.
• Potential Data Loss: If you overwrite an existing numeric ID with a string, the original entity will be lost.
• Limits on Size and Complexity: Strings have size and complexity limits, which can be restrictive.

Best Practices

• Use key names for unique string identifiers.
• Use AllocateIDs to generate unique numeric IDs for entities that do not require string identifiers.
• Ensure that manually assigned numeric IDs are truly unique before saving the entities.

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