oracle equivalent function in teradata

Oracle Functions	Teradata Functions
DECODE(A,NULL,B,C)	CASE WHEN A IS NULL THEN B ELSE C END
DECODE(A,B,C,D)	CASE A WHEN B THEN C ELSE D END
GREATEST(A,B)	CASE WHEN A >= B THEN A ELSE B END
INSTR(A,B)	INDEX(A,B)
LEAST(A,B)	CASE WHEN A <= B THEN A ELSE B END
LENGTH(A)	CHAR_LENGTH(A)
LPAD(A,B)	CAST(A AS CHAR(B))
LTRIM(A,B)	TRIM(LEADING B FROM A)
MONTHS_BETWEEN(A,B)	ABS(CAST((A - B MONTH) AS INTEGER))
RTRIM(A,B)	TRIM(TRAILING B FROM A)
TO_CHAR(ANUMBER,B)	CAST((ANUMBER (FORMAT B)) AS CHAR(X))
NVL(A,B)	COALESCE(A,B)
TO_CHAR(ADATE,B)	CAST((ADATE (FORMAT B)) AS CHAR(X))
TO_CHAR(ADATE,'MM_YY')	(ADATE (FORMAT'MM')) || '_' || (ADATE (FORMAT'YY'))
TO_CHAR(X[,F])	CAST(X AS CHAR [FORMAT F])
TRUNC(T[,F])	CAST(D AS DATE [FORMAT F])
TO_NUM(X[,F])	CAST(X AS NUMERIC [FORMAT F])
TO_DATE(X[,F])	CAST(X AS DATE [FORMAT F])
TO_NUMBER(X[,F])	CAST(X AS NUMERIC [FORMAT F])
SIGN(A)	CASE A WHEN > 0 THEN 1 WHEN < 0 THEN -1 ELSE 0 END