feat(pg_ivm): add pg_ivm extension container image

- Add pg_ivm Dockerfile with multi-stage build
- Create pg_ivm README with usage instructions for CloudNativePG clusters
- Add pg_ivm metadata.hcl with version configuration for PostgreSQL 18
- Update main README.md to include pg_ivm in the extensions table

Signed-off-by: Husn E Rabbi <shussan@gmail.com>

Author: shusaan

README.md

@@ -36,6 +36,7 @@ they are maintained by their respective authors, and PostgreSQL Debian Group
 | :--- | :--- | :--- |
 | **[pgAudit](pgaudit)** | PostgreSQL audit extension | [github.com/pgaudit/pgaudit](https://github.com/pgaudit/pgaudit) |
 | **[pg_crash](pg-crash)** | **Disruptive** fault injection and chaos engineering extension | [github.com/cybertec-postgresql/pg_crash](https://github.com/cybertec-postgresql/pg_crash) |
+| **[pg_ivm](pg_ivm)** | Incremental View Maintenance for PostgreSQL | [github.com/sraoss/pg_ivm](https://github.com/sraoss/pg_ivm) |
 | **[pgvector](pgvector)** | Vector similarity search for PostgreSQL | [github.com/pgvector/pgvector](https://github.com/pgvector/pgvector) |
 | **[PostGIS](postgis)** | Geospatial database extension for PostgreSQL | [postgis.net/](https://postgis.net/) |
 

pg_ivm/Dockerfile

@@ -0,0 +1,35 @@
+ARG BASE=ghcr.io/cloudnative-pg/postgresql:18-minimal-trixie
+FROM $BASE AS builder
+
+ARG PG_MAJOR
+ARG EXT_VERSION
+
+USER 0
+
+RUN set -eux; \
+    apt-get update; \
+    apt-get install -y --no-install-recommends \
+        build-essential \
+        ca-certificates \
+        git \
+        postgresql-server-dev-${PG_MAJOR}; \
+    # Clone and build pg_ivm from source
+    git clone --branch "v${EXT_VERSION}" --depth 1 https://github.com/sraoss/pg_ivm.git /build/pg_ivm; \
+    cd /build/pg_ivm; \
+    make USE_PGXS=1; \
+    make USE_PGXS=1 install
+
+FROM scratch
+ARG PG_MAJOR
+
+# Licenses
+COPY --from=builder /tmp/licenses/LICENSE /licenses/pg_ivm/LICENSE
+
+# Libraries
+COPY --from=builder /usr/lib/postgresql/${PG_MAJOR}/lib/pg_ivm* /lib/
+COPY --from=builder /usr/lib/postgresql/${PG_MAJOR}/lib/bitcode /usr/lib/postgresql/${PG_MAJOR}/lib/bitcode/
+
+# Share
+COPY --from=builder /usr/share/postgresql/${PG_MAJOR}/extension/pg_ivm* /share/extension/
+
+USER 65532:65532

pg_ivm/README.md

@@ -0,0 +1,60 @@
+# pg_ivm Extension
+
+[pg_ivm](https://github.com/sraoss/pg_ivm) is an open-source extension
+that provides **Incremental View Maintenance (IVM)** for PostgreSQL, allowing
+materialized views to be updated incrementally when base tables change.
+
+## Usage
+
+### 1. Add the pg_ivm extension image to your Cluster
+
+Define the `pg_ivm` extension under the `postgresql.extensions` section of
+your `Cluster` resource. For example:
+
+```yaml
+apiVersion: postgresql.cnpg.io/v1
+kind: Cluster
+metadata:
+  name: cluster-pg-ivm
+spec:
+  imageName: ghcr.io/cloudnative-pg/postgresql:18-minimal-trixie
+  instances: 1
+
+  storage:
+    size: 1Gi
+
+  postgresql:
+    extensions:
+    - name: pg_ivm
+      image:
+        reference: ghcr.io/cloudnative-pg/pg_ivm:1.13-18-trixie
+```
+
+### 2. Enable the extension in a database
+
+You can install `pg_ivm` in a specific database by creating or updating a
+`Database` resource. For example, to enable it in the `app` database:
+
+```yaml
+apiVersion: postgresql.cnpg.io/v1
+kind: Database
+metadata:
+  name: cluster-pg-ivm-app
+spec:
+  name: app
+  owner: app
+  cluster:
+    name: cluster-pg-ivm
+  extensions:
+  - name: pg_ivm
+```
+
+### 3. Verify installation
+
+Once the database is ready, connect to it with `psql` and run:
+
+```sql
+\dx
+```
+
+You should see `pg_ivm` listed among the installed extensions.

pg_ivm/metadata.hcl

@@ -0,0 +1,20 @@
+metadata = {
+  name                     = "pg_ivm"
+  sql_name                 = "pg_ivm"
+  image_name               = "pg_ivm"
+  shared_preload_libraries = []
+  extension_control_path   = []
+  dynamic_library_path     = []
+  ld_library_path          = []
+
+  versions = {
+    bookworm = {
+      // pg_ivm version from GitHub releases
+      "18" = "1.13"
+    }
+    trixie = {
+      // pg_ivm version from GitHub releases
+      "18" = "1.13"
+    }
+  }
+}