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Eugene Koifman commented on HIVE-15774: --------------------------------------- +1 pending tests > Ensure DbLockManager backward compatibility for non-ACID resources > ------------------------------------------------------------------ > > Key: HIVE-15774 > URL: https://issues.apache.org/jira/browse/HIVE-15774 > Project: Hive > Issue Type: Improvement > Components: Hive, Transactions > Reporter: Wei Zheng > Assignee: Wei Zheng > Attachments: HIVE-15774.1.patch, HIVE-15774.2.patch, > HIVE-15774.3.patch > > > In pre-ACID days, users perform operations such as INSERT with either > ZooKeeperHiveLockManager or no lock manager at all. If their workflow is > designed to take advantage of no locking and they take care of the control of > concurrency, this works well with good performance. > With ACID, if users enable transactions (i.e. using DbTxnManager & > DbLockManager), then for all the operations, different types of locks will be > acquired accordingly by DbLockManager, even for non-ACID resources. This may > impact the performance of some workflows designed for pre-ACID use cases. > A viable solution would be to differentiate the locking mode for ACID and > non-ACID resources, so that DbLockManager will continue its current behavior > for ACID tables, but will be able to acquire a less strict lock type for > non-ACID resources, thus avoiding the performance loss for those workflows. -- This message was sent by Atlassian JIRA (v6.3.15#6346)