[HIVE-11848] tables in subqueries don't get locked

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.0.0
• Fix Version/s: 1.3.0, 2.1.0
• Component/s: Locking, Transactions
• Target Version/s: 1.3.0, 2.1.0
• Assignee: Eugene Koifman
• Reporter: Eugene Koifman
• Created: 16/Sep/15 18:37
• Updated: 21/Jun/16 15:52
• Resolved: 03/May/16 22:26

Description

Consider

update acidTbl set b=19 where acidTbl.b in(select I.b from nonAcidOrcTbl I where I.a = 3)

noAcidOrcTbl doesn't get locked at all. (SHARED_WRITE is taken on acidTbl).
Same for _delete_ with subquery

This is is because the ReadEntity for nonAcidOrcTbl is skipped by

    for (ReadEntity input : plan.getInputs()) {
      if (!input.needsLock() || input.isUpdateOrDelete()) {
        // We don't want to acquire readlocks during update or delete as we'll be acquiring write
        // locks instead.
        continue;
      }

whatever sets isUpdateOrDelete() flag doesn't pay attention to whether the table is written to or not.

HIVE-10150 was a similar issue, abstractly