One database to rule them all,
One database to find them,
One database to bring them all,
And in a wrapper bind them.

PostgreSQL Foreign Data Wrapper for Oracle

oracle_fdw is a PostgreSQL extension that provides a Foreign Data Wrapper for easy and efficient access to Oracle databases.

Features:

Uses the standard compliant SQL/MED environment of PostgreSQL 9.3 and above
Supports translation of Oracle data types to similar PostgreSQL data types
WHERE conditions and ORDER BY expressions are propagated to Oracle where possible
Only the required Oracle table columns are fetched
EXPLAIN shows the remote query, EXPLAIN VERBOSE the Oracle execution plan
Should compile and run on all platforms supported by Oracle Client and PostgreSQL
Works with the regular Oracle client and Oracle Instant Client
Installable with a single CREATE EXTENSION command
Allows foreign tables based on arbitrary Oracle queries
Oracle connections are cached for the duration of the PostgreSQL session
Supports Oracle external authentication to avoid storing passwords in the database
Uses Oracle prefetching for high performance
Supports gathering statistics with ANALYZE
Supports INSERT, UPDATE and DELETE
Efficient mapping between MDSYS.SDO_GEOMETRY and PostGIS geometry
Supports IMPORT FOREIGN SCHEMA from PostgreSQL 9.5 on
Propagates 2-way joins between foreign tables to Oracle from PostgreSQL 9.6 on

Requirements:

Please report problems by opening an issue.

Commercial support through Cybertec.