[HIVE-13470] Too many locks acquired for partitioned read

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.3.0
• Component/s: Transactions
• Target Version/s: 1.3.0, 3.0.0
• Assignee: Unassigned
• Reporter: Eugene Koifman
• Created: 09/Apr/16 21:11
• Updated: 27/Feb/24 22:23

Description

consider

create table TAB_PART (a int, b int) partitioned by (p string) clustered by (a) into 2  buckets stored as orc TBLPROPERTIES ('transactional'='true')
select a from  TAB_PART where p = 'blah'

If the table is truly empty (exactly as above) then DbLockManger will acquire SHARED_READ lock on the table (for the select stmt)

If prior to Select, one runs "alter table TAB_PART add partition (p = 'blah')" then 2 SHARED_LOCKS are acquired: 1 on table and 1 on partition.

Should only get 1 partition level lock.
The behavior of lock manager is such because the generated query plan creates ReadEntity objects this way.

Todo: try actually inserting data and see if that changes anything.