The IPC specification [1] defines behavior when isDelta on a DictionaryBatch [2] is "true". I might have missed it in the specification, but I couldn't find the interpretation for what the expected behavior is when isDelta=false and and two dictionary batches with the same ID are sent.
It seems like there are two options: 1. Interpret the new dictionary batch as replacing the old one. 2. Regard this as an error condition. Based on the fact that in the "file format" dictionaries are allowed to be placed in any order relative to the record batches, I assume it is the second, but just wanted to make sure. Thanks, Micah [1] https://arrow.apache.org/docs/ipc.html [2] https://github.com/apache/arrow/blob/master/format/Message.fbs#L72
