Is it possible to access a Z custom table using ORACLE native SQL?

We have created a Z custom table in our SAP system and we would like to exchange data (read from and write to it) with an external table. Our SAP system is running on an ORACLE database, and the external table is also an ORACLE database table. As it is a custom table, and not a SAP standard table, is it possible to access it using ORACLE native SQL interface? Could it cause any problem to our SAP system?

Thank you for your help,

Regards,

Jose