Snowflake – How to compare data between tables present in Oracle and Snowflake?

There are several tools that you can use to compare data in Snowflake and Oracle.

Some options include:

  1. SQL: You can use SQL queries to extract and compare data from both Snowflake and Oracle. This can be done using the SQL command line interfaces of both databases or using a SQL client tool such as SQL Developer (for Oracle) or SnowSQL (for Snowflake).
  2. Data integration tools: There are several data integration tools that can be used to extract data from both Snowflake and Oracle and compare the data using various methods. Examples of these tools include Talend, Alteryx, and Informatica.
  3. Data comparison tools: There are also specialized data comparison tools that can be used to compare data between Snowflake and Oracle. These tools typically allow you to specify the tables or columns that you want to compare and will display the differences between the two datasets. Examples of these tools include SQL Delta, ApexSQL Diff, and Redgate SQL Data Compare.

Overall, the best tool to use will depend on your specific needs and requirements. If you are comfortable with SQL and just need to do a quick comparison, using SQL queries may be sufficient. If you need to perform more complex comparisons or integrate data from multiple sources, a data integration or comparison tool may be more appropriate.

Lets try with SQL queries:

  • Using MD5:

You can use the MD5 hash function to compare data in Snowflake and Oracle by creating a hash value for each row in the data and comparing the resulting hash values.

Here is an example of how you can use the MD5 function in a SQL query to compare data between Snowflake and Oracle:

Snowflake:

SELECT
  column1,
  column2,
  MD5(column1 || column2) AS hash_value
FROM table

Oracle:

SELECT
  column1,
  column2,
  SYS.DBMS_OBFUSCATION_TOOLKIT.MD5(input => column1 || column2) AS hash_value
FROM table

In both cases, the query will create a hash value for each row in the table using the MD5 function and return the resulting hash values along with the other columns. You can then compare the hash values between Snowflake and Oracle to see if there are any differences between the two datasets.

It is worth noting that the MD5 function is not a secure hash function and should not be used for sensitive data. There are more secure hash functions available, such as SHA-256, which may be more suitable for certain use cases.

  • Using SHA-256:

You can use the SHA-256 hash function to compare data in Snowflake and Oracle by creating a hash value for each row in the data and comparing the resulting hash values.

Here is an example of how you can use the SHA-256 function in a SQL query to compare data between Snowflake and Oracle:

Snowflake:

SELECT
  column1,
  column2,
  SHA2(column1 || column2, 256) AS hash_value
FROM table

Oracle:

SELECT
  column1,
  column2,
  SYS.DBMS_CRYPTO.HASH(input => column1 || column2, type => SYS.DBMS_CRYPTO.HASH_SH256) AS hash_value
FROM table

In both cases, the query will create a hash value for each row in the table using the SHA-256 function and return the resulting hash values along with the other columns. You can then compare the hash values between Snowflake and Oracle to see if there are any differences between the two datasets.

Overall, SHA-256 is a more secure hash function than MD5 and is generally considered to be more suitable for use with sensitive data. However, it is worth noting that even secure hash functions are not completely immune to collision attacks, so it is always important to carefully evaluate the security needs of your application and choose the appropriate hash function accordingly.

 

If you are unsure how to compare your data in Snowflake or would like to speak with an expert to learn more about them, Anyon ConsultingBI group can help! Our database experts and consultants that can answer any questions on customize dashboards, help with your database implementation, optimize your database platform, and much more. Contact us today to learn more about our  Custom Database Development.

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