[jira] [Created] (HIVE-21388) Constant UDF is not pushed to JDBCStorage Handler

["Jesus Camacho Rodriguez (JIRA)" <ji...@apache.org>]

Jesus Camacho Rodriguez created HIVE-21388:
----------------------------------------------

             Summary: Constant UDF is not pushed to JDBCStorage Handler
                 Key: HIVE-21388
                 URL: https://issues.apache.org/jira/browse/HIVE-21388
             Project: Hive
          Issue Type: Improvement
          Components: CBO, StorageHandler
    Affects Versions: 4.0.0
            Reporter: Daniel Dai
            Assignee: Jesus Camacho Rodriguez


A query involve a Hive UDF which produce a constant value does not push to JDBC table. Replacing the UDF with a constant push down works. Ideally, Hive shall first do constant folding and then push the computation.

Here is the example:
{code}
explain select PRINCIPAL_NAME from sys.TBL_PRIVS where PRINCIPAL_NAME=current_user();
+----------------------------------------------------+
|                      Explain                       |
+----------------------------------------------------+
| Plan optimized by CBO.                             |
|                                                    |
| Stage-0                                            |
|   Fetch Operator                                   |
|     limit:-1                                       |
|     Select Operator [SEL_3]                        |
|       Output:["_col0"]                             |
|       Filter Operator [FIL_2]                      |
|         predicate:(_col5 = 'hrt_qa')               |
|         Select Operator [SEL_1]                    |
|           Output:["_col5"]                         |
|           TableScan [TS_0]                         |
|             Output:["principal_name"],properties:{"hive.sql.query":"SELECT `tbl_grant_id`, `create_time`, `grant_option`, `grantor`, `grantor_type`, `principal_name`, `principal_type`, `tbl_priv`, `tbl_id`, `authorizer`\nFROM `TBL_PRIVS`","hive.sql.query.fieldNames":"tbl_grant_id,create_time,grant_option,grantor,grantor_type,principal_name,principal_type,tbl_priv,tbl_id,authorizer","hive.sql.query.fieldTypes":"bigint,int,int,string,string,string,string,string,bigint,string","hive.sql.query.split":"true"} |
|                                                    |
+----------------------------------------------------+
{code}
If I replace current_user() with a constant, the predicate is pushed to table scan.

Also, setting annotation deterministic=true and make initialize() return a ConstantObjectInspector of GenericUDFCurrentUser does not make a difference.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)