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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 situation. > 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 (v6.3.4#6332)