[ https://issues.apache.org/jira/browse/HIVE-18888?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16434519#comment-16434519 ]
Alexander Kolbasov commented on HIVE-18888: ------------------------------------------- Hmm, interesting. Looks like this is intentional - for maps with concurrent access there is no way to distinguish between the missing value and the NULL value. I am not sure whether this was an issue with the original use of wrapped maps. > Replace synchronizedMap with ConcurrentHashMap > ---------------------------------------------- > > Key: HIVE-18888 > URL: https://issues.apache.org/jira/browse/HIVE-18888 > Project: Hive > Issue Type: Bug > Components: Hive > Affects Versions: 3.0.0, 2.3.3 > Reporter: Alexander Kolbasov > Assignee: Alexander Kolbasov > Priority: Major > Fix For: 3.0.0 > > Attachments: HIVE-18888.01.patch, HIVE-18888.02.patch > > > There are a bunch of places that use Collections.synchronizedMap instead of > ConcurrentHashMap which are better. We should search/replace the uses. -- This message was sent by Atlassian JIRA (v7.6.3#76005)