Zoltan Ivanfi commented on AVRO-1340:

I agree that the generic fallback mechanism may be overkill, I just argued that 
even though it is not useful for card suits, it can make sense with different 
types of enums.

My main concern about introducing a default value for unknown values is that 1) 
it requires writing boiler-plate code, but 2) this requirement is not enforced 
and if the boiler-plate is not added initially it is impossible to handle the 
situation later. On the other hand, even with these shortcomings, the 
possibility to specify a default value is still better than the current 

> use default to allow old readers to specify default enum value when 
> encountering new enum symbols
> -------------------------------------------------------------------------------------------------
>                 Key: AVRO-1340
>                 URL: https://issues.apache.org/jira/browse/AVRO-1340
>             Project: Avro
>          Issue Type: Improvement
>          Components: spec
>         Environment: N/A
>            Reporter: Jim Donofrio
>            Priority: Minor
> The schema resolution page says:
> > if both are enums:
> > if the writer's symbol is not present in the reader's enum, then an
> error is signalled.
> This makes it difficult to use enum's because you can never add a enum value 
> and keep old reader's compatible. Why not use the default option to refer to 
> one of enum values so that when a old reader encounters a enum ordinal it 
> does not recognize, it can default to the optional schema provided one. If 
> the old schema does not provide a default then the older reader can continue 
> to fail as it does today.

This message was sent by Atlassian JIRA

Reply via email to