How Can I connect a custom data source without (ARP) connector (JDBC)

Hey all, I’m intrested in how to connect a (custom) data source without using arp. Because arp has to use jdbc as protocol, but we want to use a high performanced protocol like (protobuf based), we have large datasets to read (maybe 500mb per result) and mostly batch queries, jdbc maybe not fast enough for batch data read, does it?