Yes, you can use checksum or hash values to compare the data in two tables from different databases in Sybase. This approach can be more efficient than loading the entire record for comparison, as it only requires comparing the key and hash values, rather than the entire record.

You can use the CHECKSUM() or HASHBYTES() functions in Sybase to generate a unique value for each record in a table. You can then use these values to compare the data in two tables from different databases.
Here is an example of how you can use the CHECKSUM() function to compare the data in two tables from different databases:

SELECT CHECKSUM(*) FROM db1.table1
SELECT CHECKSUM(*) FROM db2.table2

You can then compare the values returned by the two SELECT statements to determine if the data in the two tables is the same.

For comparing the data in tables you can use a framework like Apache NiFi, which is an open-source data integration tool that can be used to automate data flows between different databases. It provides a user-friendly interface and a wide variety of built-in processors for tasks such as data extraction, data transformation, and data comparison.

In Java, you can use the library like Apache Commons DbUtils, which is a simple JDBC wrapper that provides a number of useful utility methods for working with databases. It also provides a number of utility classes for working with databases, including a class for comparing the data in two tables.

Please keep in mind that the specific approach and tools you use to compare the data in two tables from different databases may depend on the specific requirements of your application. It's also good to have a backup of the database before doing this process, in case anything goes wrong.