PREHOOK: query: DESCRIBE FUNCTION when
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION when
POSTHOOK: type: DESCFUNCTION
CASE WHEN a THEN b [WHEN c THEN d]* [ELSE e] END - When a = true, returns b; when c = true, return d; else return e
PREHOOK: query: DESCRIBE FUNCTION EXTENDED when
PREHOOK: type: DESCFUNCTION
POSTHOOK: query: DESCRIBE FUNCTION EXTENDED when
POSTHOOK: type: DESCFUNCTION
CASE WHEN a THEN b [WHEN c THEN d]* [ELSE e] END - When a = true, returns b; when c = true, return d; else return e
Example:
 SELECT
 CASE
   WHEN deptno=1 THEN Engineering
   WHEN deptno=2 THEN Finance
   ELSE admin
 END,
 CASE
   WHEN zone=7 THEN Americas
   ELSE Asia-Pac
 END
 FROM emp_details
PREHOOK: query: EXPLAIN
SELECT CASE
        WHEN 1=1 THEN 2
        WHEN 1=3 THEN 4
        ELSE 5
       END,
       CASE
        WHEN 6=7 THEN 8
        ELSE 9
       END,
       CASE
        WHEN 10=11 THEN 12
        WHEN 13=13 THEN 14
       END,
       CASE
        WHEN 15=16 THEN 17
        WHEN 18=19 THEN 20
       END,
       CASE
        WHEN 21=22 THEN NULL
        WHEN 23=23 THEN 24
       END,
       CASE
        WHEN 25=26 THEN 27
        WHEN 28=28 THEN NULL
       END
FROM src tablesample (1 rows)
PREHOOK: type: QUERY
POSTHOOK: query: EXPLAIN
SELECT CASE
        WHEN 1=1 THEN 2
        WHEN 1=3 THEN 4
        ELSE 5
       END,
       CASE
        WHEN 6=7 THEN 8
        ELSE 9
       END,
       CASE
        WHEN 10=11 THEN 12
        WHEN 13=13 THEN 14
       END,
       CASE
        WHEN 15=16 THEN 17
        WHEN 18=19 THEN 20
       END,
       CASE
        WHEN 21=22 THEN NULL
        WHEN 23=23 THEN 24
       END,
       CASE
        WHEN 25=26 THEN 27
        WHEN 28=28 THEN NULL
       END
FROM src tablesample (1 rows)
POSTHOOK: type: QUERY
STAGE DEPENDENCIES:
  Stage-0 is a root stage

STAGE PLANS:
  Stage: Stage-0
    Fetch Operator
      limit: -1
      Processor Tree:
        TableScan
          alias: src
          Row Limit Per Split: 1
          Statistics: Num rows: 500 Data size: 5312 Basic stats: COMPLETE Column stats: COMPLETE
          Select Operator
            expressions: 2 (type: int), 9 (type: int), 14 (type: int), null (type: void), CASE WHEN (false) THEN (null) WHEN (true) THEN (24) END (type: int), CASE WHEN (false) THEN (27) WHEN (true) THEN (null) END (type: int)
            outputColumnNames: _col0, _col1, _col2, _col3, _col4, _col5
            Statistics: Num rows: 500 Data size: 10000 Basic stats: COMPLETE Column stats: COMPLETE
            ListSink

PREHOOK: query: SELECT CASE
        WHEN 1=1 THEN 2
        WHEN 1=3 THEN 4
        ELSE 5
       END,
       CASE
        WHEN 6=7 THEN 8
        ELSE 9
       END,
       CASE
        WHEN 10=11 THEN 12
        WHEN 13=13 THEN 14
       END,
       CASE
        WHEN 15=16 THEN 17
        WHEN 18=19 THEN 20
       END,
       CASE
        WHEN 21=22 THEN NULL
        WHEN 23=23 THEN 24
       END,
       CASE
        WHEN 25=26 THEN 27
        WHEN 28=28 THEN NULL
       END
FROM src tablesample (1 rows)
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: SELECT CASE
        WHEN 1=1 THEN 2
        WHEN 1=3 THEN 4
        ELSE 5
       END,
       CASE
        WHEN 6=7 THEN 8
        ELSE 9
       END,
       CASE
        WHEN 10=11 THEN 12
        WHEN 13=13 THEN 14
       END,
       CASE
        WHEN 15=16 THEN 17
        WHEN 18=19 THEN 20
       END,
       CASE
        WHEN 21=22 THEN NULL
        WHEN 23=23 THEN 24
       END,
       CASE
        WHEN 25=26 THEN 27
        WHEN 28=28 THEN NULL
       END
FROM src tablesample (1 rows)
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
2	9	14	NULL	24	NULL
PREHOOK: query: -- Allow compatible types to be used in return value
SELECT CASE
        WHEN 1=1 THEN 123.0BD
        ELSE 0.0BD
       END,
       CASE
        WHEN 1=1 THEN 123
        WHEN 1=2 THEN 1.0
        ELSE 222.02BD
       END,
       CASE
        WHEN 1=1 THEN 'abcd'
        WHEN 1=2 THEN cast('efgh' as varchar(10))
        ELSE cast('ijkl' as char(4))
       END
FROM src tablesample (1 rows)
PREHOOK: type: QUERY
PREHOOK: Input: default@src
#### A masked pattern was here ####
POSTHOOK: query: -- Allow compatible types to be used in return value
SELECT CASE
        WHEN 1=1 THEN 123.0BD
        ELSE 0.0BD
       END,
       CASE
        WHEN 1=1 THEN 123
        WHEN 1=2 THEN 1.0
        ELSE 222.02BD
       END,
       CASE
        WHEN 1=1 THEN 'abcd'
        WHEN 1=2 THEN cast('efgh' as varchar(10))
        ELSE cast('ijkl' as char(4))
       END
FROM src tablesample (1 rows)
POSTHOOK: type: QUERY
POSTHOOK: Input: default@src
#### A masked pattern was here ####
123	123.0	abcd