I need to convert below function in from DB2 to Oracle, can anybody help? I have no idea about DB2

Question

I need to convert below function from DB2 to Oracle, can anybody help? I have no idea about DB2 :

CREATE FUNCTION READMSGS(   SOURCE_NAME    VARCHAR(12),  SOURCE_SCHEMA  VARCHAR(12), SOURCE_VERSION    VARCHAR(64),  EXPLAIN_LEVEL     CHAR(1))                            
RETURNS TABLE ( ID varchar(20),
                  DEPTNUM INT,
                  AVGSAL DECIMAL (9,2),
                  EMPCNT INT,
                  WORKDEPT INT )
  LANGUAGE SQL
  DETERMINISTIC
  NO EXTERNAL ACTION
  READS SQL DATA
  RETURN 
  
  SELECT       ID,
               DEPTNUM,
               AVGSAL,
               EMPCNT,
               WORKDEPT
  FROM EMP3  ;

Answer 1

All Parameters are unused which bit weird.You need to remove them if they are unused.

It looks simple to me it is simply returning a custom table/type from function. Here is my weak effort to solve your question

1st step would be to create custom type if you don't have any

create or replace type CustomerType(
        ID Varchar2(20),
        DEPTNUM Number,
        AVGSAL Number,
        EMPCNT Number,
        WORKDEPT Number
    ); 

Secondly modified function in plsql

FUNCTION EXPLAINSMSGS(SOURCE_NAME in VARCHAR2,SOURCE_SCHEMA in VARCHAR2, SOURCE_VERSION in VARCHAR2,EXPLAIN_LEVEL in Varchar2) return record is
  l_customType   CustomerType;
  l_ID Varchar2(20);
  l_DEPTNUM Number;
  l_AVGSAL Nubmer;
  l_EMPCNT Number,
  l_WORKDEPT Varchar2(100);

  Begin
    SELECT     ID,
               DEPTNUM,
               AVGSAL,
               EMPCNT,
               WORKDEPT
    INTO       l_ID,
               l_DEPTNUM,
               l_AVGSAL,
               l_EMPCNT,
               l_WORKDEPT  
  FROM EMP3  ;

  l_customType :=CustomerType(l_ID,l_DEPTNUM,l_AVGSAL,l_EMPCNT,l_WORKDEPT);

  Return l_customType;

  End;

Answer 2

The DB2 function is declared as DETERMINISTIC. It means it will return the same set of rows for n number of invocation. Glancing through this DB2 code, you will not need a function in Oracle, rather create a view for the select statement as in

CREATE VIEW explainmsgs AS
      SELECT  
            id,
            deptnum,
            avgsal,
            empcnt,
            workdept
      FROM emp3  
/