Install orafce for AlloyDB Omni

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This page describes how to manually add the orafce extension to an existing AlloyDB Omni installation. The orafce extension provides functions and operators that emulate a subset of functions and packages from the Oracle database. This extension simplifies migration of applications from Oracle to PostgreSQL-compatible databases such as AlloyDB Omni.

Before you begin

Install AlloyDB Omni using the RPM orchestrator.

Add orafce to your AlloyDB Omni installation

To add the orafce extension to your AlloyDB Omni cluster, follow these steps manually on all the database nodes including read pool nodes in your cluster.

  1. Add the PostgreSQL Yum Repository:

    sudo dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-9-x86_64/pgdg-redhat-repo-latest.noarch.rpm

  2. Install PostgreSQL server and development packages:

    sudo dnf install -y "postgresql18-server"

  3. Install the Orafce extension:

    sudo dnf install -y orafce_18

  4. Create required symlinks so the extensions are in the expected paths:

    set -e
PGVER="18"

sudo mkdir -p "/usr/lib/postgresql/${PGVER}/share/extension"

for file in /usr/pgsql-${PGVER}/share/extension/*; do
  target="/usr/lib/postgresql/${PGVER}/share/extension/$(basename "$file")"
  if [[ ! -e "$target" ]]; then
    sudo ln -s "$file" "$target" || (echo "Failed to link \"$file\" to \"$target\", exiting." && exit 1)
    echo "Created extension link for $(basename "$file")"
  else
    echo "Target $target already exists."
  fi
done

sudo mkdir -p "/usr/lib/postgresql/${PGVER}/lib"

for file in /usr/pgsql-${PGVER}/lib/*; do
  target="/usr/lib/postgresql/${PGVER}/lib/$(basename "$file")"
  if [[ ! -e "$target" ]]; then
    sudo ln -s "$file" "$target" || (echo "Failed to link \"$file\" to \"$target\", exiting." && exit 1)
    echo "Created lib link for $(basename "$file")"
  else
    echo "Target $target already exists."
  fi
done

  5. Connect to your database and run the CREATE EXTENSION command to enable orafce:

    For instructions on connecting to your instance, see Connect to AlloyDB Omni.

    CREATE EXTENSION IF NOT EXISTS ORAFCE;

  6. Confirm that orafce is installed and enabled:

    SELECT oracle.sysdate();

    The output is similar to the following:

    postgres=# SELECT oracle.sysdate();
sysdate
---------------------
2025-12-12 16:36:30
(1 row)