OceanBase tenants run in MySQL mode or Oracle mode at creation time. The choice fixes SQL dialect, drivers, and migration tooling. You cannot flip modes on the same tenant; plan a new tenant and data move if you need to change.
OceanBase sets MySQL or Oracle compatibility mode when you create the tenant. Choose the mode that matches your application drivers and SQL dialect before go-live.
MySQL mode
- Backtick identifiers,
LIMIT,AUTO_INCREMENT. - Fits apps that already use MySQL drivers (JDBC via OBProxy).
Oracle mode
ROWNUM,DUAL,VARCHAR2, PL/SQL packages (subset documented for your version).- Use Oracle JDBC thin driver or OceanBase Oracle tenant URL.
Migration impact
| Feature | MySQL mode | Oracle mode |
|---|---|---|
| Sequences | AUTO_INCREMENT | SEQUENCE + trigger patterns |
| Pagination | LIMIT n | ROWNUM / FETCH |
| Empty string | ” allowed | ” treated as NULL in Oracle mode |
Run application integration tests in staging with production driver settings before cutover.