1 · Terminates the handshake
The full Oracle Net connect + TTC negotiation + challenge/response auth (12c PBKDF2 with mutual server proof, or the 11g MD5 verifier).
dbSaci
Point an unmodified Oracle driver at dbSaci and it connects, authenticates, and runs a session — while the database behind it is PostgreSQL or MariaDB.
What it is
Section titled “What it is”dbSaci speaks Oracle’s TNS / TTC wire protocol on the front and
PostgreSQL or MariaDB on the back. An unmodified Oracle client — python-oracledb (thin),
the Oracle JDBC thin driver, ODP.NET managed — points at dbSaci instead of at an
Oracle database, and dbSaci:
2 · Translates the SQL
The Oracle SQL/PL-SQL dialect it understands is rewritten to the selected backend; binds are sent as backend parameters.
3 · Runs it on the backend
One backend round trip to PostgreSQL + orafce,
or MariaDB 11.4+ in SQL_MODE=ORACLE.
4 · Re-frames the result
The backend result is re-encoded into Oracle’s binary framing and streamed back batch by batch.
The application keeps its Oracle driver, its connection-string shape, and most of its SQL. Nothing about the database it actually talks to is Oracle.
How this differs from IvorySQL
Section titled “How this differs from IvorySQL”IvorySQL is a fork of the PostgreSQL
server that builds Oracle SQL / PL-SQL compatibility — an Oracle parse mode,
PL/iSQL, packages, NUMBER/DATE semantics — into the engine. It goes deep on
the dialect, but it still speaks the PostgreSQL wire protocol: the
application connects with a PostgreSQL driver, not its Oracle one.
dbSaci is the other way round. It speaks Oracle’s TNS/TTC wire protocol, so
the unmodified Oracle driver — ojdbc, ODP.NET, python-oracledb — connects to it
exactly as it would to Oracle, and the database behind it is stock PostgreSQL or
MariaDB. The trade is the SQL/PL-SQL surface: dbSaci only covers what its
translation layer plus the selected backend compatibility facilities can express.
They solve different problems. Reach for IvorySQL if you can repoint the app at a new database and want broad Oracle SQL semantics; reach for dbSaci if the app and its Oracle client have to stay exactly as they are.
What worksDrivers, SQL, DDL, triggers, transactions, operations.
What doesn'tNot yet vs structurally impossible on stock PostgreSQL.
Compatibility matrixThe detailed per-area breakdown.
How it worksThe query path, wire negotiation, and testing.