Ben Kietzman created ARROW-12632: ------------------------------------ Summary: [C++][Dataset][Compute] Add support for dictionary_encode to Expression Key: ARROW-12632 URL: https://issues.apache.org/jira/browse/ARROW-12632 Project: Apache Arrow Issue Type: New Feature Components: C++ Affects Versions: 4.0.0 Reporter: Ben Kietzman Assignee: Ben Kietzman Fix For: 5.0.0
dictionary_encode should be usable in the context of ExecuteScalarExpression, but is not currently supported because it requires mutable state (the hash table). Currently scanning assumes that Expression state will not be mutated so only one instance is initialized and is shared between all threads of execution. Supporting dictionary_encode will require adding support for multiple states to Expression and usage of that by dataset scans. -- This message was sent by Atlassian Jira (v8.3.4#803005)