Can AllocateIDs Generate Unique String Identifiers for Datastore Entities?

Using AllocateIDs to Generate Unique Identifiers for Datastore Entities

Question:

When assigning a unique identifier to datastore entities, can AllocateIDs be used to generate strings instead of integers, and if so, is it safe to do so?

Answer:

Understanding Entity Keys

An entity key in datastore can either have a string "name" identifier or an integer "intID" identifier. AllocateIDs generates intIDs, so it's not directly applicable to generating strings.

Unique Identifier Generation

Datastore automatically assigns intIDs to new entities without specified identifiers. AllocateIDs allows developers to reserve a range of intIDs for manual assignment and ensures they will not be used by the datastore, guaranteeing uniqueness within that range.

Consideration for Manual Identifier Assignment

In most cases, manual identifier assignment is not necessary. However, if a unique property of the entity is available, it can be used as the identifier to ensure uniqueness naturally.

Allocating String Identifiers

AllocateIDs cannot be used to allocate string identifiers. String identifiers must be assigned explicitly by the application and must be unique within the entity kind. The datastore does not provide a guaranteed mechanism for allocating unique strings.

Conclusion

While AllocateIDs is a valuable tool for generating unique intIDs, it's not suitable for generating string identifiers. For string identifiers, developers must implement logic to ensure uniqueness, as the datastore does not provide a built-in allocation mechanism.

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