What are options for a Delphi app to migrate away from BDE if using Oracle database

You will need to learn about the differences between BDE and other architectures. Whether you plan to move to dbExpress or not you should read and learn from this whitepaper.

The architecture of dbExpress is an intentional architecture, designed to address critical flaws not only in the BDE's lowest levels, but also in its upper levels (the TTable/TQuery components) and architecture. Understanding the reasons for those changes, and the limitations in the BDE that they address, is a key element in moving your app off the BDE, to anything.

As for your contention on performance, I like to see people use real data, not form opinions based on hand-waving, or adjectives like "fast" imparted upon objects, without experimental backing.

I have not personally used DOA, but if I wasn't going to use dbExpress, that would be the next thing I would evaluate, for Oracle-only environments. nevertheless, I wouldn't assume that dbExpress is slower, without testing both in my own environment.

Updated: Originally I mentioned Delphi OCI, but it turns out it's out of date, and not very active. DelphiOCI project on sourceforge, works with Delphi 7 and before, not on unicode delphi, and only with older (Oracle 8i and older) oracle versions... If this was able to work in my environment, I'd have tried it. Oh, and it's GPL. Okay. Not so great.

Both ODAC and DOA (although DOA development is pretty stale lateley) will give you access to Oracle features dbExpress and other generic DB access libraries will usually not allow access to. If your application does support Oracle only, and doesn't need to support other DBs, it's IMHO far better to exploit Oracle capabilites fully.The ease of port depends on how you wrote you BDE component code. ODAC has tools to simplify BDE porting (I never used them, though), while AFAIK DOA has not.DOA TOracleQuery is not a TDataset descendant, and thereby is not a direct TQuery replacement, although it has less overhead, and thereby has good performance, while TOracleDaset is the only dataset-like component.I would not use the ODAC direct TCP connection to Oracle without the Oracle client but for very special needs - it is an unsupported (by Oracle) connection, I'd prefer to use Oracle Instant Client if a small (relatively...) footprint is needed, at least it is a fully supported option and let you (or your customers) open support request with Oracle if needed.