fix: fixing teradata doc (#513)

* fixing teradata doc

* and the installation

* fixing link and adding additional note

* fixing link and adding additional note

README.md

@@ -135,7 +135,9 @@ The [Examples](https://github.com/GoogleCloudPlatform/professional-services-data
 #### Row Validations
 
 (Note: Row hash validation is currently only supported for BigQuery, Teradata, and Imapala/Hive. Struct and array 
-data types are not currently supported.)
+data types are not currently supported. In addition, please note that SHA256 is not a supported function on teradata 
+systems. If you wish to perform this comparison on teradata you will need to 
+[deploy a UDF to perform the conversion](https://github.com/akuroda/teradata-udf-sha2/blob/master/src/sha256.c).)
 
 Below is the command syntax for row validations. In order to run row level
 validations you need to pass a `--primary-key` flag which defines what field(s)
@@ -466,6 +468,9 @@ and run a SHA256() hash and compare the source and target results. Since each ro
 be returned in the result set, it is recommended to utilize the `--use-random-row` feature
 to validate a subset of the table.
 
+Please note that SHA256 is not a supported function on teradata systems. If you wish to perform
+this comparison on teradata you will need to [deploy a UDF to perform the conversion](https://github.com/akuroda/teradata-udf-sha2/blob/master/src/sha256.c).
+
 Comparison field validations (`--comp-fields column`) involve an value comparison of the
 column values. These values will be compared via a JOIN on their corresponding primary
 key and will be evaluated for an exact match.

docs/installation.md

@@ -105,7 +105,7 @@ If you require Teradata and have a license, install the `teradatasql` package.
 python -m pip install teradatasql
 ```
 
-If you plan to perform row level hashing on teradata, you will need to install a UDF that implements sha256 on your Teradata instance. An example can be found [here](.https://downloads.teradata.com/forum/extensibility/sha-2-udfs-for-teradata).
+If you plan to perform row level hashing on teradata, you will need to install a UDF that implements sha256 on your Teradata instance. An example can be found [here](https://downloads.teradata.com/forum/extensibility/sha-2-udfs-for-teradata).
 
 After installing the Data Validation package you will
 have access to the `data-validation -h` or `python -m data_validation -h`