1. Connect to Teradata

Use Teradata SQL Assistant, BTEQ, or any preferred SQL execution tool.

Connect using your credentials and select the database containing the data you wish to export.

2. Prepare Data for Export

• Identify the tables or data you want to move.
• Cleanse and transform the data as necessary to ensure compatibility with Snowflake.

3. Export Data to a File

• Execute a query to export the data to a flat file (CSV, TSV, etc.).
• You may use the `EXPORT` command or any other method provided by Teradata for data extraction.
• Ensure you include headers in the export if you want to use them in Snowflake for column mapping.

```sql

.EXPORT DATA FILE = <file_path>

SELECT * FROM <your_table>;

```

1. Choose a Staging Area

You can use an internal stage in Snowflake or a cloud storage service such as Amazon S3, Azure Blob Storage, or Google Cloud Storage.

2. Transfer Files to Staging Area

• If using cloud storage, upload the files using the service's web interface, CLI, or SDKs.
• Ensure the files are in a secure location and that Snowflake has the necessary permissions to access them.

1. Login to Snowflake

Use the Snowflake web interface or connect using SnowSQL.

2. Create a File Format

Define a file format that matches the format of the exported data from Teradata.

```sql

CREATE OR REPLACE FILE FORMAT my_file_format

TYPE = 'CSV'

FIELD_DELIMITER = ','

SKIP_HEADER = 1

FIELD_OPTIONALLY_ENCLOSED_BY = '"'

ERROR_ON_COLUMN_COUNT_MISMATCH = TRUE

NULL_IF = ('\\N');

```

1. Create a Stage

Define a stage that references the location of the uploaded data files.

```sql

-- For an internal stage:

CREATE OR REPLACE STAGE my_internal_stage

FILE_FORMAT = my_file_format;

-- For an external stage (e.g., Amazon S3):

CREATE OR REPLACE STAGE my_external_stage

URL = 's3://mybucket/myfolder/'

CREDENTIALS = (AWS_KEY_ID = 'myKeyId' AWS_SECRET_KEY = 'mySecretKey')

FILE_FORMAT = my_file_format;

```

1. Create a Target Table

Define a table in Snowflake that matches the schema of the Teradata source data.

```sql

CREATE OR REPLACE TABLE my_table (

    column1 datatype1,

    column2 datatype2,

    ...

);

```

2. Copy Data into the Table

Use the `COPY INTO` command to load data from the stage into the Snowflake table.

```sql

-- For an internal stage:

COPY INTO my_table

FROM @my_internal_stage

FILE_FORMAT = (FORMAT_NAME = my_file_format);

-- For an external stage:

COPY INTO my_table

FROM @my_external_stage

FILE_FORMAT = (FORMAT_NAME = my_file_format);

```

3. Monitor the Load Process

Check the load process for errors and ensure that the data is loaded correctly.

```sql

SELECT * FROM TABLE(INFORMATION_SCHEMA.COPY_HISTORY(TABLE_NAME => 'my_table', START_TIME => dateadd(hours, -1, current_timestamp())));

```

4. Validate the Data:

Query the Snowflake table and validate that the data has been loaded correctly and completely.

1. Remove Temporary Files

Delete the exported data files from the staging area to prevent storage clutter and maintain security.

2. Review and Optimize

Review the entire process for optimizations such as automating repetitive tasks, improving data transformation, or refining the Snowflake table design for better performance.

By following these steps, you can manually move data from Teradata to Snowflake without the use of third-party connectors or integrations. Remember to handle sensitive data with care throughout the process and to comply with data governance and security policies.