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Eugene Koifman updated HIVE-18570: ---------------------------------- Attachment: HIVE-18570.04-branch-3.patch > ACID IOW implemented using base may delete too much data > -------------------------------------------------------- > > Key: HIVE-18570 > URL: https://issues.apache.org/jira/browse/HIVE-18570 > Project: Hive > Issue Type: Bug > Components: Transactions > Reporter: Sergey Shelukhin > Assignee: Eugene Koifman > Priority: Blocker > Attachments: HIVE-18570.01-branch-3.patch, HIVE-18570.01.patch, > HIVE-18570.02-branch-3.patch, HIVE-18570.03-branch-3.patch, > HIVE-18570.04-branch-3.patch > > > Suppose we have a table with delta_0 insert data. > Txn 1 starts an insert into delta_1. > Txn 2 starts an IOW into base_2. > Txn 2 commits. > Txn 1 commits after txn 2 but its results would be invisible. > Txn 2 deletes rows committed by txn 1 that according to standard ACID > semantics it could have never observed and affected; this sequence of events > is only possible under read-uncommitted isolation level (so, 2 deletes rows > written by 1 before 1 commits them). > This is if we look at IOW as transactional delete+insert. Otherwise we are > just saying IOW performs "semi"-transactional delete. > If 1 ran an update on rows instead of an insert, and 2 still ran an > IOW/delete, row lock conflict (or equivalent) should cause one of them to > fail. -- This message was sent by Atlassian JIRA (v7.6.3#76005)