amrishlal commented on a change in pull request #6710: URL: https://github.com/apache/incubator-pinot/pull/6710#discussion_r605324977
########## File path: pinot-common/src/main/java/org/apache/pinot/common/utils/DataTable.java ########## @@ -80,4 +85,85 @@ double[] getDoubleArray(int rowId, int colId); String[] getStringArray(int rowId, int colId); + + /* The MetadataKey is used in V3, where we present metadata as Map<MetadataKey, String> + * ATTENTION: + * - Don't change existing keys. + * - Don't remove existing keys. + * - Always add new keys to the end. + * Otherwise, backward compatibility will be broken. + */ + enum MetadataKey { + UNKNOWN("unknown"), Review comment: Is UNKNOWN really needed? Can we get rid of it? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org