@avashokkumar How about importing your data directly to the database? If you are using for example PostgreSQL, there are CLI tools for data import available. You might need to adapt your data to the schema, though. But you can just append the data that way.
An alternative that might even be easier is to use the REST / GraphQL interface to add data without overwriting. You could write a little loader script, for example in JavaScript to do that easily.