METADATA TESTING IN ETL

1. DATA TYPE LENGTH CHECK

   The length of source column data type should be greater than or equal to the target column data type.

2. DATA TYPE CHECK

  Ensure that source and target data type should be same.

  But there is a possibility that the target data type is different from source.

Example:- If source is Oracle database and target is HANA.

ORACLE		HANA
CHAR		NVARCHAR
VARCHAR2		NVARCHAR
NVARCHAR2		NVARCHAR
NCHAR		NVARCHAR
DATE		NVARCHAR(8)
TIMESTAMP		NVARCHAR (40)
NUMBER (p=0 or p>31, s=0) *p - precision *s - scale		DOUBLE
NUMBER (0<p<=4, s=0)		SMALLINT
NUMBER (4<p<=9, s=0)		INTEGER
NUMBER (9<p<=31, s=0)		DECIMAL
NUMBER (p<=31, 0<s<=14)		DECIMAL
NUMBER(all others)		DOUBLE
FLOAT		DOUBLE

3.CONSTRAINT CHECK

Constraint checking involves verifying

i) Primary key constraint

ii) Not NULL constraint-

But if your source is a table, and target is  HANA view, then you can't validate not null constraint.