Eugene Koifman created HIVE-13622:
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Summary: WriteSet tracking optimizations
Key: HIVE-13622
URL: https://issues.apache.org/jira/browse/HIVE-13622
Project: Hive
Issue Type: Bug
Components: Transactions
Affects Versions: 1.3.0, 2.1.0
Reporter: Eugene Koifman
Assignee: Eugene Koifman
HIVE-13395 solves the the lost update problem with some inefficiencies.
1. TxhHandler.OperationType is currently derived from LockType. This doesn't
distinguish between Update and Delete but would be useful. See comments in
TxnHandler. Should be able to pass in Insert/Update/Delete info from client
into TxnHandler.
2. TxnHandler.addDynamicPartitions() should know the OperationType as well from
the client. It currently extrapolates it from TXN_COMPONENTS. This works but
requires extra SQL statements and is thus less performant. It will not work
multi-stmt txns. See comments in the code.
3. TxnHandler.checkLock() see more comments around
"isPartOfDynamicPartitionInsert". If TxnHandler knew whether it is being
called as part of an op running with dynamic partitions, it could be more
efficient. In that case we don't have to write to TXN_COMPONENTS at all during
lock acquisition. Conversely, if not running with DynPart then, we can kill
current txn on lock grant rather than wait until commit time.
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