[jira] [Created] (ARROW-5767) [Format] Permit dictionary replacements in IPC protocol

["Wes McKinney (JIRA)" <ji...@apache.org>]

Wes McKinney created ARROW-5767:
-----------------------------------

             Summary: [Format] Permit dictionary replacements in IPC protocol
                 Key: ARROW-5767
                 URL: https://issues.apache.org/jira/browse/ARROW-5767
             Project: Apache Arrow
          Issue Type: New Feature
          Components: Format
            Reporter: Wes McKinney
             Fix For: 1.0.0


We permit dictionaries to grow using the {{isDelta}} property in the IPC protocol. I think it should be allowed for the same dictionary ID to appear in an IPC protocol stream but with {{isDelta=false}}. This would indicate that the dictionary in that message is to replace any prior-observed ones in subsequent record batches.

For example, we might have dictionary batches in a stream:

{code}
id: 0 isDelta: false values: [a, b, c]
id: 0 isDelta: true values [d]
id 0 isDelta: false values [c, a, b]
{code}

Such data could easily be produced by a stream producer that is creating dictionaries in different execution threads. 



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)