[jira] [Reopened] (HIVE-21074) Hive bucketed table query pruning does not work for IS NOT NULL condition

["Ádám Szita (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-21074?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Ádám Szita reopened HIVE-21074:
-------------------------------
      Assignee: Ádám Szita  (was: Thai Bui)

> Hive bucketed table query pruning does not work for IS NOT NULL condition
> -------------------------------------------------------------------------
>
>                 Key: HIVE-21074
>                 URL: https://issues.apache.org/jira/browse/HIVE-21074
>             Project: Hive
>          Issue Type: Bug
>          Components: Logical Optimizer
>    Affects Versions: 3.1.0, 3.0.0, 3.1.1
>            Reporter: Thai Bui
>            Assignee: Ádám Szita
>            Priority: Minor
>             Fix For: 4.0.0
>
>         Attachments: HIVE-21074.patch
>
>
> The current version of bucket pruning skips all the predicates when it detects that one of the predicates is a compound type (e.g. NOT(IS_NULL) ) when evaluating AND logical operators.
> This logic is faulty since as long as one of the AND operators is a bucketed column (_col_ = *literal*), the *literal* value of that _col_ should be considered in the bucket pruning optimization no matter what. For example:
> SELECT * FROM tbl WHERE bucketed_col = 1 AND (some_compound_expr)
> Then the the value '*1'* should be considered for pruning in the query plan. This limitation has manifested into a simpler case where a table that I am trying to optimized using bucketing technique is not effective when IS NOT NULL is used. Since IS NOT NULL is parsed into NOT(IS_NULL) (a compound expression), the pruning phase is completed skipped causing unnecessary tasks to be spawned. For instance:
> SELECT * FROM tbl WHERE bucketed_col = 1 AND some_other_col IS NOT NULL
> Will not trigger bucket pruning logic and perform a full table scan.



--
This message was sent by Atlassian Jira
(v8.20.1#820001)