How to install Oracle in PostgreSQL

Galaxy Glossary

How do I install Oracle (oracle_fdw) in PostgreSQL?

install Oracle loads the oracle_fdw extension so PostgreSQL can query remote Oracle databases.

Welcome to the Galaxy, Guardian!
You'll be receiving a confirmation email

Follow us on twitter :)

Oops! Something went wrong while submitting the form.

Description

Example H2

Example H3

Why install Oracle (oracle_fdw) in PostgreSQL?

install Oracle lets you read and write Oracle tables from PostgreSQL using Foreign Data Wrapper (FDW) technology. It removes ETL overhead and keeps your analytics in one place.

What are the prerequisites?

You need PostgreSQL superuser rights, Oracle Instant Client ≥ 11.2, matching OS architecture, and the oracle_fdw source code.Ensure ORACLE_HOME and LD_LIBRARY_PATH (or PATH on Windows) point to the Instant Client libraries.

How do I compile oracle_fdw?

Unpack the source, set ORACLE_HOME and PATH, then run make followed by make install under the postgres-owned shell. On Debian/Ubuntu use sudo apt-get install postgresql-server-dev-15 to get build headers first.

How do I install Oracle inside a database?

Connect as a superuser and issue the CREATE EXTENSION command shown below.This registers FDW objects and functions.

What roles and privileges are needed?

The database role executing CREATE EXTENSION must be a superuser or have CREATE on the target schema and USAGE on extension’s objects.

How do I create an Oracle server definition?

Use CREATE SERVER with the Oracle connect descriptor. Store credentials via CREATE USER MAPPING.

How can I query ecommerce tables in Oracle?

Declare foreign tables that mirror Oracle structures (Customers, Orders, Products, OrderItems).Queries then work like local tables and support joins, filters, and aggregates.

Can I push filters to Oracle?

Yes. oracle_fdw pushes down WHERE, JOIN, and aggregation operations when they are compatible with Oracle SQL, reducing network I/O.

Best practices for production use?

Use connection pooling with idle_in_transaction_session_timeout set, restrict large data types, and monitor Oracle session counts. Version-lock oracle_fdw against PostgreSQL upgrades.

Common pitfalls to avoid

Missing Oracle environment variables cause libclntsh.so not found errors. Mismatched 32/64-bit binaries lead to loader failures.

Why How to install Oracle in PostgreSQL is important

How to install Oracle in PostgreSQL Example Usage


-- Join PostgreSQL data with Oracle Orders table
SELECT c.id, c.name, o.total_amount
FROM Customers   AS c
JOIN Orders      AS o  ON o.customer_id = c.id
WHERE o.order_date >= CURRENT_DATE - INTERVAL '30 days';

How to install Oracle in PostgreSQL Syntax


CREATE EXTENSION [IF NOT EXISTS] oracle_fdw [WITH SCHEMA schema_name];

-- Create remote Oracle server
CREATE SERVER oracle_srv
  FOREIGN DATA WRAPPER oracle_fdw
  OPTIONS (dbserver '//host:1521/ORCLPDB');

-- Map local role to Oracle credentials
CREATE USER MAPPING FOR app_user
  SERVER oracle_srv
  OPTIONS (user 'ECOM_APP', password 'secret');

-- Import specific ecommerce tables
IMPORT FOREIGN SCHEMA "ECOM"
  LIMIT TO (CUSTOMERS, ORDERS, PRODUCTS, ORDERITEMS)
  FROM SERVER oracle_srv INTO public;

Common Mistakes

Installing oracle_fdw without matching Oracle Client architecture. Mix-and-match 32-bit and 64-bit libraries triggers linker errors. Fix by downloading the correct Instant Client build.
Forgetting to set ORACLE_HOME and LD_LIBRARY_PATH before starting PostgreSQL. The server process can’t find Oracle libraries, so the extension fails to load. Export variables in the service unit or .bashrc.