diff --git a/.github/workflows/nix-dependency-analysis.yml b/.github/workflows/nix-dependency-analysis.yml
new file mode 100644
index 000000000..f8f5463a4
--- /dev/null
+++ b/.github/workflows/nix-dependency-analysis.yml
@@ -0,0 +1,130 @@
+name: Nix Dependency Analysis
+
+on:
+  pull_request:
+    paths:
+      - "flake.lock"
+      - "flake.nix"
+      - "nix/**"
+      - "ci/**"
+      - ".github/workflows/nix-dependency-analysis.yml"
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: "PR number to analyze"
+        required: false
+        type: number
+
+permissions:
+  contents: read
+  pull-requests: write
+  id-token: write # For AWS OIDC (Nix cache)
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  dependency-analysis:
+    name: Package Dependency Analysis
+    runs-on: blacksmith-4vcpu-ubuntu-2404
+    steps:
+      - name: Checkout repository
+        uses: supabase/postgres/.github/actions/shared-checkout@HEAD
+
+      - name: Install Nix
+        uses: ./.github/actions/nix-install-ephemeral
+        with:
+          push-to-cache: "false"
+        env:
+          DEV_AWS_ROLE: ${{ secrets.DEV_AWS_ROLE }}
+          NIX_SIGN_SECRET_KEY: ${{ secrets.NIX_SIGN_SECRET_KEY }}
+
+      - name: Run dependency analysis
+        id: dep-analysis
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          PR_URL="${{ github.event.pull_request.html_url || format('https://github.com/{0}/pull/{1}', github.repository, github.event.inputs.pr_number) }}"
+          echo "Analyzing PR: $PR_URL"
+          ./ci/postgresql-diff.sh "$PR_URL"
+
+          # Read the generated markdown file
+          MARKDOWN_FILE=$(find . -maxdepth 1 -name "postgresql-diff-pr-*.md" -type f | head -1)
+          if [ -n "$MARKDOWN_FILE" ]; then
+            echo "markdown_file=$MARKDOWN_FILE" >> "$GITHUB_OUTPUT"
+            echo "Generated file: $MARKDOWN_FILE"
+          else
+            echo "Error: No markdown file generated"
+            exit 1
+          fi
+
+      - name: Find existing dependency comment
+        uses: peter-evans/find-comment@v3
+        id: fc-dep
+        if: github.event_name == 'pull_request'
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: "github-actions[bot]"
+          body-includes: "<!-- dependency-diff-analysis -->"
+
+      - name: Create or update dependency comment
+        uses: peter-evans/create-or-update-comment@v4
+        if: github.event_name == 'pull_request'
+        with:
+          comment-id: ${{ steps.fc-dep.outputs.comment-id }}
+          issue-number: ${{ github.event.pull_request.number }}
+          body-path: ${{ steps.dep-analysis.outputs.markdown_file }}
+          edit-mode: replace
+
+  extension-analysis:
+    name: Extension Dependency Analysis
+    runs-on: blacksmith-4vcpu-ubuntu-2404
+    steps:
+      - name: Checkout repository
+        uses: supabase/postgres/.github/actions/shared-checkout@HEAD
+
+      - name: Install Nix
+        uses: ./.github/actions/nix-install-ephemeral
+        with:
+          push-to-cache: "false"
+        env:
+          DEV_AWS_ROLE: ${{ secrets.DEV_AWS_ROLE }}
+          NIX_SIGN_SECRET_KEY: ${{ secrets.NIX_SIGN_SECRET_KEY }}
+
+      - name: Run extension analysis
+        id: ext-analysis
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          PR_URL="${{ github.event.pull_request.html_url || format('https://github.com/{0}/pull/{1}', github.repository, github.event.inputs.pr_number) }}"
+          echo "Analyzing PR: $PR_URL"
+          ./ci/extensions-diff.sh "$PR_URL"
+
+          # Read the generated markdown file
+          MARKDOWN_FILE=$(find . -maxdepth 1 -name "extensions-diff-pr-*.md" -type f | head -1)
+          if [ -n "$MARKDOWN_FILE" ]; then
+            echo "markdown_file=$MARKDOWN_FILE" >> "$GITHUB_OUTPUT"
+            echo "Generated file: $MARKDOWN_FILE"
+          else
+            echo "Error: No markdown file generated"
+            exit 1
+          fi
+
+      - name: Find existing extension comment
+        uses: peter-evans/find-comment@v3
+        id: fc-ext
+        if: github.event_name == 'pull_request'
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: "github-actions[bot]"
+          body-includes: "<!-- extension-diff-analysis -->"
+
+      - name: Create or update extension comment
+        uses: peter-evans/create-or-update-comment@v4
+        if: github.event_name == 'pull_request'
+        with:
+          comment-id: ${{ steps.fc-ext.outputs.comment-id }}
+          issue-number: ${{ github.event.pull_request.number }}
+          body-path: ${{ steps.ext-analysis.outputs.markdown_file }}
+          edit-mode: replace
diff --git a/ci/extensions-diff.sh b/ci/extensions-diff.sh
new file mode 100755
index 000000000..0965a08d5
--- /dev/null
+++ b/ci/extensions-diff.sh
@@ -0,0 +1,433 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Validate PR URL argument
+if [ $# -ne 1 ]; then
+	echo "Usage: $0 <github-pr-url>"
+	echo "Example: $0 https://github.com/supabase/postgres/pull/2002"
+	exit 1
+fi
+
+PR_URL="$1"
+
+# Extract PR number from URL
+# Support formats:
+# - https://github.com/supabase/postgres/pull/2002
+# - github.com/supabase/postgres/pull/2002
+PR_NUMBER=$(echo "$PR_URL" | grep -oE '[0-9]+$')
+
+if [ -z "$PR_NUMBER" ]; then
+	echo "Error: Invalid PR URL format. Expected: https://github.com/supabase/postgres/pull/NUMBER"
+	exit 1
+fi
+
+# Verify required tools are installed
+if ! command -v gh &>/dev/null; then
+	echo "Error: GitHub CLI (gh) is not installed"
+	echo "Install from: https://cli.github.com/"
+	exit 1
+fi
+
+if ! command -v git &>/dev/null; then
+	echo "Error: git is not installed"
+	exit 1
+fi
+
+if ! command -v jq &>/dev/null; then
+	echo "Error: jq is not installed"
+	exit 1
+fi
+
+# Fetch PR information using gh API
+echo "Fetching PR #$PR_NUMBER information..."
+
+if ! PR_JSON=$(gh pr view "$PR_NUMBER" --repo supabase/postgres --json headRefName,headRefOid,baseRefName 2>/dev/null) || [ -z "$PR_JSON" ]; then
+	echo "Error: Failed to fetch PR #$PR_NUMBER from supabase/postgres"
+	exit 1
+fi
+
+PR_BRANCH=$(echo "$PR_JSON" | jq -r '.headRefName')
+PR_COMMIT=$(echo "$PR_JSON" | jq -r '.headRefOid')
+BASE_BRANCH=$(echo "$PR_JSON" | jq -r '.baseRefName')
+
+echo "PR Branch: $PR_BRANCH"
+echo "PR HEAD: $PR_COMMIT"
+echo "Base Branch: $BASE_BRANCH"
+
+# Handle non-develop base branch
+if [ "$BASE_BRANCH" != "develop" ]; then
+	echo "Warning: PR base is '$BASE_BRANCH' instead of 'develop'"
+	echo "Continuing with base branch: $BASE_BRANCH"
+	echo ""
+fi
+
+# Get the current HEAD commit of the base branch
+echo "Fetching $BASE_BRANCH HEAD commit..."
+
+BASE_COMMIT=$(gh api "/repos/supabase/postgres/git/refs/heads/$BASE_BRANCH" --jq '.object.sha')
+
+if [ -z "$BASE_COMMIT" ]; then
+	echo "Error: Failed to fetch HEAD commit for branch '$BASE_BRANCH'"
+	exit 1
+fi
+
+echo "$BASE_BRANCH HEAD: $BASE_COMMIT"
+echo ""
+
+# Create tmpdir for both clones
+TMPDIR_BASE="${TMPDIR:-/tmp}/extension-diff-$$"
+OLD_DIR="$TMPDIR_BASE/base-$BASE_BRANCH"
+NEW_DIR="$TMPDIR_BASE/pr-$PR_NUMBER"
+
+echo "Using directories:"
+echo "  OLD_DIR: $OLD_DIR"
+echo "  NEW_DIR: $NEW_DIR"
+echo ""
+
+# Setup output file (use absolute path since we'll be changing directories)
+ORIGINAL_DIR="$(pwd)"
+OUTPUT_FILE="$ORIGINAL_DIR/extensions-diff-pr-${PR_NUMBER}.md"
+echo "Output will be written to: $OUTPUT_FILE"
+echo ""
+
+# Initialize output file with header
+cat >"$OUTPUT_FILE" <<EOF
+<!-- extension-diff-analysis -->
+# PostgreSQL Extension Dependency Analysis: PR #${PR_NUMBER}
+
+- **PR:** ${PR_URL}
+- **Base Branch:** ${BASE_BRANCH} (${BASE_COMMIT:0:7})
+- **PR Branch:** ${PR_BRANCH} (${PR_COMMIT:0:7})
+- **Analysis Date:** $(date '+%Y-%m-%d %H:%M:%S')
+
+EOF
+
+# Create temporary file for collecting MAJOR updates
+MAJOR_UPDATES_FILE="/tmp/major-updates-$$.txt"
+: >"$MAJOR_UPDATES_FILE" # Initialize empty file
+
+# Trap to cleanup on exit
+cleanup() {
+	rm -f "$MAJOR_UPDATES_FILE"
+	rm -f /tmp/old-*-deps-$$.txt /tmp/new-*-deps-$$.txt
+	rm -rf "$TMPDIR_BASE"
+}
+
+trap cleanup EXIT
+
+# Function to ensure repository is at a specific commit
+ensure_repo_at_commit() {
+	local target_dir="$1"
+	local branch_name="$2"
+	local commit_sha="$3"
+	local repo_url="https://github.com/supabase/postgres.git"
+
+	if [ -d "$target_dir/.git" ]; then
+		echo "Repository exists at $target_dir, updating..."
+		cd "$target_dir"
+
+		# Fetch the specific commit (shallow)
+		# First try to fetch just the commit
+		if ! git fetch --depth=1 origin "$commit_sha" 2>/dev/null; then
+			# If that fails, fetch the branch
+			git fetch --depth=1 origin "$branch_name"
+		fi
+
+		# Checkout the target commit
+		git checkout "$commit_sha" 2>/dev/null || git checkout "origin/$branch_name"
+
+	else
+		echo "Cloning repository to $target_dir..."
+		mkdir -p "$(dirname "$target_dir")"
+
+		# Shallow clone with depth=1 for the specific branch
+		git clone --depth=1 --branch "$branch_name" "$repo_url" "$target_dir"
+
+		cd "$target_dir"
+
+		# If we need a specific commit that's not HEAD, fetch it
+		current_sha=$(git rev-parse HEAD)
+		if [ "$current_sha" != "$commit_sha" ]; then
+			git fetch --depth=1 origin "$commit_sha"
+			git checkout "$commit_sha"
+		fi
+	fi
+}
+
+# Setup base branch checkout (OLD_DIR)
+ensure_repo_at_commit "$OLD_DIR" "$BASE_BRANCH" "$BASE_COMMIT"
+
+# Setup PR branch checkout (NEW_DIR)
+ensure_repo_at_commit "$NEW_DIR" "$PR_BRANCH" "$PR_COMMIT"
+
+# Build all variants in both directories
+echo "Building in $OLD_DIR..."
+cd "$OLD_DIR"
+nix build ".#psql_15/bin" -o result-psql_15
+nix build ".#psql_17/bin" -o result-psql_17
+nix build ".#psql_orioledb-17/bin" -o result-psql_orioledb-17
+
+echo ""
+echo "Building in $NEW_DIR..."
+cd "$NEW_DIR"
+nix build ".#psql_15/bin" -o result-psql_15
+nix build ".#psql_17/bin" -o result-psql_17
+nix build ".#psql_orioledb-17/bin" -o result-psql_orioledb-17
+
+# Function to extract package name and version from store path
+parse_store_path() {
+	local path="$1"
+	basename "$path" | sed 's/^[a-z0-9]*-//' | sed 's/-\([0-9]\)/ \1/' | head -c 80
+}
+
+# Function to compare versions and return change type
+compare_versions() {
+	local old="$1"
+	local new="$2"
+
+	# Check if either version looks like a git commit hash (7+ consecutive hex chars)
+	if echo "$old" | grep -qE '\b[0-9a-f]{7,}\b'; then
+		echo "CHANGED"
+		return
+	fi
+	if echo "$new" | grep -qE '\b[0-9a-f]{7,}\b'; then
+		echo "CHANGED"
+		return
+	fi
+
+	# Extract version numbers
+	old_ver=$(echo "$old" | grep -oE '[0-9]+(\.[0-9]+)*' | head -1)
+	new_ver=$(echo "$new" | grep -oE '[0-9]+(\.[0-9]+)*' | head -1)
+
+	if [ -z "$old_ver" ] || [ -z "$new_ver" ]; then
+		echo "CHANGED"
+		return
+	fi
+
+	# If version is just a single number (no dots), treat as CHANGED
+	if ! echo "$old_ver" | grep -q '\.'; then
+		echo "CHANGED"
+		return
+	fi
+	if ! echo "$new_ver" | grep -q '\.'; then
+		echo "CHANGED"
+		return
+	fi
+
+	# Split into major.minor.patch
+	IFS='.' read -ra old_parts <<<"$old_ver"
+	IFS='.' read -ra new_parts <<<"$new_ver"
+
+	old_major=${old_parts[0]:-0}
+	old_minor=${old_parts[1]:-0}
+	old_patch=${old_parts[2]:-0}
+
+	new_major=${new_parts[0]:-0}
+	new_minor=${new_parts[1]:-0}
+	new_patch=${new_parts[2]:-0}
+
+	# Compare versions
+	if [ "$new_major" -gt "$old_major" ]; then
+		echo "MAJOR"
+	elif [ "$new_major" -lt "$old_major" ]; then
+		echo "DOWNGRADE"
+	elif [ "$new_minor" -gt "$old_minor" ]; then
+		echo "MINOR"
+	elif [ "$new_minor" -lt "$old_minor" ]; then
+		echo "DOWNGRADE"
+	elif [ "$new_patch" -gt "$old_patch" ]; then
+		echo "PATCH"
+	elif [ "$new_patch" -lt "$old_patch" ]; then
+		echo "DOWNGRADE"
+	else
+		echo "CHANGED"
+	fi
+}
+
+# Function to get all extensions for a PostgreSQL version
+get_extension_list() {
+	local pg_version="$1"
+
+	# Get extension names from versions.json that support this PG version
+	jq -r --arg pgver "$pg_version" '
+        to_entries[] |
+        .key as $ext_name |
+        .value |
+        to_entries[] |
+        select(.value.postgresql | map(tostring) | contains([$pgver])) |
+        $ext_name
+    ' "$OLD_DIR/nix/ext/versions.json" | sort -u
+}
+
+# Function to analyze extension dependencies for a PostgreSQL variant
+analyze_variant_extension_deps() {
+	local pg_version="$1"
+	local variant_name="$2"
+	local result_suffix="$3"
+
+	echo "## $variant_name Extension Dependencies"
+	echo ""
+
+	# Check if both result symlinks exist
+	if [ ! -e "$OLD_DIR/result-$result_suffix" ] || [ ! -e "$NEW_DIR/result-$result_suffix" ]; then
+		echo "Skipping $variant_name (not built in one or both directories)"
+		echo ""
+		return
+	fi
+
+	# Get list of extensions
+	extensions=$(get_extension_list "$pg_version")
+
+	if [ -z "$extensions" ]; then
+		echo "No extensions found for PostgreSQL $pg_version"
+		echo ""
+		return
+	fi
+
+	# Export pg_version for use in subshell
+	export CURRENT_PG_VERSION="$pg_version"
+
+	# For each extension, compare its dependencies
+	echo "$extensions" | while read -r ext; do
+		# Get extension shared library files in both builds (.so on Linux, .dylib on macOS)
+		old_so=$(find "$OLD_DIR/result-$result_suffix/lib" \( -name "${ext}*.so" -o -name "${ext}*.dylib" \) 2>/dev/null | head -1 || echo "")
+		new_so=$(find "$NEW_DIR/result-$result_suffix/lib" \( -name "${ext}*.so" -o -name "${ext}*.dylib" \) 2>/dev/null | head -1 || echo "")
+
+		if [ -z "$old_so" ] || [ -z "$new_so" ]; then
+			continue
+		fi
+
+		# Get dependency closure for the extension .so file
+		old_deps=$(nix-store -qR "$old_so" 2>/dev/null | sort || echo "")
+		new_deps=$(nix-store -qR "$new_so" 2>/dev/null | sort || echo "")
+
+		# Parse and compare
+		echo "$old_deps" | while read -r path; do
+			parse_store_path "$path"
+		done | sort >"/tmp/old-$ext-deps-$$.txt"
+
+		echo "$new_deps" | while read -r path; do
+			parse_store_path "$path"
+		done | sort >"/tmp/new-$ext-deps-$$.txt"
+
+		# Check if there are any changes
+		if ! diff -q "/tmp/old-$ext-deps-$$.txt" "/tmp/new-$ext-deps-$$.txt" >/dev/null 2>&1; then
+			echo "### Extension: $ext"
+			echo ""
+			echo "| Dependency | Old Version | New Version | Change Type |"
+			echo "|------------|-------------|-------------|-------------|"
+
+			# Get all unique package names
+			cat "/tmp/old-$ext-deps-$$.txt" "/tmp/new-$ext-deps-$$.txt" | cut -d' ' -f1 | sort -u | while read -r pkg; do
+				old_match=$(grep "^$pkg " "/tmp/old-$ext-deps-$$.txt" | head -1 || echo "")
+				new_match=$(grep "^$pkg " "/tmp/new-$ext-deps-$$.txt" | head -1 || echo "")
+
+				if [ -n "$old_match" ] && [ -n "$new_match" ]; then
+					if [ "$old_match" != "$new_match" ]; then
+						old_ver="${old_match#"$pkg "}"
+						new_ver="${new_match#"$pkg "}"
+						change_type=$(compare_versions "$old_match" "$new_match")
+						echo "| $pkg | $old_ver | $new_ver | $change_type |"
+
+						# Collect MAJOR updates for summary
+						if [ "$change_type" = "MAJOR" ]; then
+							echo "$CURRENT_PG_VERSION|$ext|$pkg|$old_ver|$new_ver" >>"$MAJOR_UPDATES_FILE"
+						fi
+					fi
+				elif [ -n "$old_match" ]; then
+					old_ver="${old_match#"$pkg "}"
+					echo "| $pkg | $old_ver | - | REMOVED |"
+				elif [ -n "$new_match" ]; then
+					new_ver="${new_match#"$pkg "}"
+					echo "| $pkg | - | $new_ver | ADDED |"
+				fi
+			done
+
+			echo ""
+
+			# Add raw nix-store output
+			echo ""
+			echo "<details>"
+			echo "<summary>Raw Dependency Tree</summary>"
+			echo ""
+			echo "\`\`\`"
+			echo "Old ($old_so):"
+			echo "$old_deps"
+			echo ""
+			echo "New ($new_so):"
+			echo "$new_deps"
+			echo "\`\`\`"
+			echo ""
+			echo "</details>"
+			echo ""
+		fi
+	done
+}
+
+# Function to generate summary of MAJOR updates
+generate_summary() {
+	if [ ! -s "$MAJOR_UPDATES_FILE" ]; then
+		echo "## Summary"
+		echo ""
+		echo "No extensions had dependencies with MAJOR version updates."
+		echo ""
+	else
+		echo "## Summary"
+		echo ""
+		echo "The following extensions have dependencies that underwent **MAJOR** version updates:"
+		echo ""
+		echo "| PostgreSQL Version | Extension | Dependency | Old Version | New Version |"
+		echo "|--------------------|-----------|------------|-------------|-------------|"
+
+		while IFS='|' read -r pg_ver ext dep old_ver new_ver; do
+			echo "| $pg_ver | $ext | $dep | $old_ver | $new_ver |"
+		done <"$MAJOR_UPDATES_FILE"
+
+		echo ""
+	fi
+}
+
+# Redirect analysis output to file (wrap in details/summary for collapsible section)
+{
+	echo "<details>"
+	echo "<summary>Full Analysis Results</summary>"
+	echo ""
+
+	# Analyze all three variants
+	analyze_variant_extension_deps "15" "PostgreSQL 15" "psql_15"
+	analyze_variant_extension_deps "17" "PostgreSQL 17" "psql_17"
+	analyze_variant_extension_deps "orioledb-17" "OrioleDB 17" "psql_orioledb-17"
+
+	echo "</details>"
+} >>"$OUTPUT_FILE"
+
+# Generate and insert summary at the top of results
+SUMMARY_CONTENT=$(generate_summary)
+
+# Insert summary after the header but before PostgreSQL version sections
+# We need to insert it after the header (line with "Analysis Date") and before first "##" heading
+if [[ "$OSTYPE" == "darwin"* ]]; then
+	# macOS - create temp file with proper structure
+	{
+		# Read header (including bullet point lines)
+		sed -n '1,/^- \*\*Analysis Date:/p' "$OUTPUT_FILE"
+		echo ""
+		# Insert summary
+		echo "$SUMMARY_CONTENT"
+		# Append rest of file (everything after the header)
+		sed -n '/^- \*\*Analysis Date:/,$p' "$OUTPUT_FILE" | tail -n +2
+	} >"$OUTPUT_FILE.tmp"
+	mv "$OUTPUT_FILE.tmp" "$OUTPUT_FILE"
+else
+	# GNU/Linux - similar approach
+	{
+		sed -n '1,/^- \*\*Analysis Date:/p' "$OUTPUT_FILE"
+		echo ""
+		echo "$SUMMARY_CONTENT"
+		sed -n '/^- \*\*Analysis Date:/,$p' "$OUTPUT_FILE" | tail -n +2
+	} >"$OUTPUT_FILE.tmp"
+	mv "$OUTPUT_FILE.tmp" "$OUTPUT_FILE"
+fi
+
+echo "Analysis complete!"
+echo "Results written to: $OUTPUT_FILE"
diff --git a/ci/postgresql-diff.sh b/ci/postgresql-diff.sh
new file mode 100755
index 000000000..4677c7084
--- /dev/null
+++ b/ci/postgresql-diff.sh
@@ -0,0 +1,397 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Validate PR URL argument
+if [ $# -ne 1 ]; then
+	echo "Usage: $0 <github-pr-url>"
+	echo "Example: $0 https://github.com/supabase/postgres/pull/2002"
+	exit 1
+fi
+
+PR_URL="$1"
+
+# Extract PR number from URL
+# Support formats:
+# - https://github.com/supabase/postgres/pull/2002
+# - github.com/supabase/postgres/pull/2002
+PR_NUMBER=$(echo "$PR_URL" | grep -oE '[0-9]+$')
+
+if [ -z "$PR_NUMBER" ]; then
+	echo "Error: Invalid PR URL format. Expected: https://github.com/supabase/postgres/pull/NUMBER"
+	exit 1
+fi
+
+# Verify required tools are installed
+if ! command -v gh &>/dev/null; then
+	echo "Error: GitHub CLI (gh) is not installed"
+	echo "Install from: https://cli.github.com/"
+	exit 1
+fi
+
+if ! command -v git &>/dev/null; then
+	echo "Error: git is not installed"
+	exit 1
+fi
+
+if ! command -v jq &>/dev/null; then
+	echo "Error: jq is not installed"
+	exit 1
+fi
+
+# Fetch PR information using gh API
+echo "Fetching PR #$PR_NUMBER information..."
+
+if ! PR_JSON=$(gh pr view "$PR_NUMBER" --repo supabase/postgres --json headRefName,headRefOid,baseRefName 2>/dev/null) || [ -z "$PR_JSON" ]; then
+	echo "Error: Failed to fetch PR #$PR_NUMBER from supabase/postgres"
+	exit 1
+fi
+
+PR_BRANCH=$(echo "$PR_JSON" | jq -r '.headRefName')
+PR_COMMIT=$(echo "$PR_JSON" | jq -r '.headRefOid')
+BASE_BRANCH=$(echo "$PR_JSON" | jq -r '.baseRefName')
+
+echo "PR Branch: $PR_BRANCH"
+echo "PR HEAD: $PR_COMMIT"
+echo "Base Branch: $BASE_BRANCH"
+
+# Handle non-develop base branch
+if [ "$BASE_BRANCH" != "develop" ]; then
+	echo "Warning: PR base is '$BASE_BRANCH' instead of 'develop'"
+	echo "Continuing with base branch: $BASE_BRANCH"
+	echo ""
+fi
+
+# Get the current HEAD commit of the base branch
+echo "Fetching $BASE_BRANCH HEAD commit..."
+
+BASE_COMMIT=$(gh api "/repos/supabase/postgres/git/refs/heads/$BASE_BRANCH" --jq '.object.sha')
+
+if [ -z "$BASE_COMMIT" ]; then
+	echo "Error: Failed to fetch HEAD commit for branch '$BASE_BRANCH'"
+	exit 1
+fi
+
+echo "$BASE_BRANCH HEAD: $BASE_COMMIT"
+echo ""
+
+# Create tmpdir for both clones
+TMPDIR_BASE="${TMPDIR:-/tmp}/dependency-diff-$$"
+OLD_DIR="$TMPDIR_BASE/base-$BASE_BRANCH"
+NEW_DIR="$TMPDIR_BASE/pr-$PR_NUMBER"
+
+echo "Using directories:"
+echo "  OLD_DIR: $OLD_DIR"
+echo "  NEW_DIR: $NEW_DIR"
+echo ""
+
+# Setup output file (use absolute path since we'll be changing directories)
+ORIGINAL_DIR="$(pwd)"
+OUTPUT_FILE="$ORIGINAL_DIR/postgresql-diff-pr-${PR_NUMBER}.md"
+echo "Output will be written to: $OUTPUT_FILE"
+echo ""
+
+# Initialize output file with header
+cat >"$OUTPUT_FILE" <<EOF
+<!-- dependency-diff-analysis -->
+# PostgreSQL Package Dependency Analysis: PR #${PR_NUMBER}
+
+- **PR:** ${PR_URL}
+- **Base Branch:** ${BASE_BRANCH} (${BASE_COMMIT:0:7})
+- **PR Branch:** ${PR_BRANCH} (${PR_COMMIT:0:7})
+- **Analysis Date:** $(date '+%Y-%m-%d %H:%M:%S')
+
+EOF
+
+# Create temporary file for collecting MAJOR updates
+MAJOR_UPDATES_FILE="/tmp/major-updates-$$.txt"
+: >"$MAJOR_UPDATES_FILE" # Initialize empty file
+
+# Trap to cleanup on exit
+cleanup() {
+	rm -f "$MAJOR_UPDATES_FILE"
+	rm -f /tmp/old-*-deps-$$.txt /tmp/new-*-deps-$$.txt
+	rm -f /tmp/old-*-names-$$.txt /tmp/new-*-names-$$.txt
+	rm -rf "$TMPDIR_BASE"
+}
+
+trap cleanup EXIT
+
+# Function to ensure repository is at a specific commit
+ensure_repo_at_commit() {
+	local target_dir="$1"
+	local branch_name="$2"
+	local commit_sha="$3"
+	local repo_url="https://github.com/supabase/postgres.git"
+
+	if [ -d "$target_dir/.git" ]; then
+		echo "Repository exists at $target_dir, updating..."
+		cd "$target_dir"
+
+		# Fetch the specific commit (shallow)
+		# First try to fetch just the commit
+		if ! git fetch --depth=1 origin "$commit_sha" 2>/dev/null; then
+			# If that fails, fetch the branch
+			git fetch --depth=1 origin "$branch_name"
+		fi
+
+		# Checkout the target commit
+		git checkout "$commit_sha" 2>/dev/null || git checkout "origin/$branch_name"
+
+	else
+		echo "Cloning repository to $target_dir..."
+		mkdir -p "$(dirname "$target_dir")"
+
+		# Shallow clone with depth=1 for the specific branch
+		git clone --depth=1 --branch "$branch_name" "$repo_url" "$target_dir"
+
+		cd "$target_dir"
+
+		# If we need a specific commit that's not HEAD, fetch it
+		current_sha=$(git rev-parse HEAD)
+		if [ "$current_sha" != "$commit_sha" ]; then
+			git fetch --depth=1 origin "$commit_sha"
+			git checkout "$commit_sha"
+		fi
+	fi
+}
+
+# Setup base branch checkout (OLD_DIR)
+ensure_repo_at_commit "$OLD_DIR" "$BASE_BRANCH" "$BASE_COMMIT"
+
+# Setup PR branch checkout (NEW_DIR)
+ensure_repo_at_commit "$NEW_DIR" "$PR_BRANCH" "$PR_COMMIT"
+
+# Build all variants in both directories
+echo "Building in $OLD_DIR..."
+cd "$OLD_DIR"
+nix build ".#psql_15/bin" -o result-psql_15
+nix build ".#psql_17/bin" -o result-psql_17
+nix build ".#psql_orioledb-17/bin" -o result-psql_orioledb-17
+
+echo ""
+echo "Building in $NEW_DIR..."
+cd "$NEW_DIR"
+nix build ".#psql_15/bin" -o result-psql_15
+nix build ".#psql_17/bin" -o result-psql_17
+nix build ".#psql_orioledb-17/bin" -o result-psql_orioledb-17
+
+echo ""
+
+# Function to extract package name and version from store path
+parse_store_path() {
+	local path="$1"
+	basename "$path" | sed 's/^[a-z0-9]*-//' | sed 's/-\([0-9]\)/ \1/' | head -c 80
+}
+
+# Function to compare versions and return change type
+compare_versions() {
+	local old="$1"
+	local new="$2"
+
+	# Check if either version looks like a git commit hash (7+ consecutive hex chars)
+	if echo "$old" | grep -qE '\b[0-9a-f]{7,}\b'; then
+		echo "CHANGED"
+		return
+	fi
+	if echo "$new" | grep -qE '\b[0-9a-f]{7,}\b'; then
+		echo "CHANGED"
+		return
+	fi
+
+	# Extract version numbers
+	old_ver=$(echo "$old" | grep -oE '[0-9]+(\.[0-9]+)*' | head -1)
+	new_ver=$(echo "$new" | grep -oE '[0-9]+(\.[0-9]+)*' | head -1)
+
+	if [ -z "$old_ver" ] || [ -z "$new_ver" ]; then
+		echo "CHANGED"
+		return
+	fi
+
+	# If version is just a single number (no dots), treat as CHANGED
+	if ! echo "$old_ver" | grep -q '\.'; then
+		echo "CHANGED"
+		return
+	fi
+	if ! echo "$new_ver" | grep -q '\.'; then
+		echo "CHANGED"
+		return
+	fi
+
+	# Split into major.minor.patch
+	IFS='.' read -ra old_parts <<<"$old_ver"
+	IFS='.' read -ra new_parts <<<"$new_ver"
+
+	old_major=${old_parts[0]:-0}
+	old_minor=${old_parts[1]:-0}
+	old_patch=${old_parts[2]:-0}
+
+	new_major=${new_parts[0]:-0}
+	new_minor=${new_parts[1]:-0}
+	new_patch=${new_parts[2]:-0}
+
+	# Compare versions
+	if [ "$new_major" -gt "$old_major" ]; then
+		echo "MAJOR"
+	elif [ "$new_major" -lt "$old_major" ]; then
+		echo "DOWNGRADE"
+	elif [ "$new_minor" -gt "$old_minor" ]; then
+		echo "MINOR"
+	elif [ "$new_minor" -lt "$old_minor" ]; then
+		echo "DOWNGRADE"
+	elif [ "$new_patch" -gt "$old_patch" ]; then
+		echo "PATCH"
+	elif [ "$new_patch" -lt "$old_patch" ]; then
+		echo "DOWNGRADE"
+	else
+		echo "CHANGED"
+	fi
+}
+
+# Function to analyze a PostgreSQL variant
+analyze_variant_deps() {
+	local variant="$1"
+	local variant_name="$2"
+	local result_suffix="$3"
+
+	# Check if both result symlinks exist
+	if [ ! -e "$OLD_DIR/result-$result_suffix" ] || [ ! -e "$NEW_DIR/result-$result_suffix" ]; then
+		echo "## $variant_name Dependency Changes"
+		echo ""
+		echo "Skipping $variant_name (not built in one or both directories)"
+		echo ""
+		return
+	fi
+
+	echo "## $variant_name Dependency Changes"
+	echo ""
+
+	# Export variant for use in subshell
+	export CURRENT_PG_VERSION="$variant"
+
+	echo "Extracting $variant_name dependencies..."
+	nix path-info -r "$OLD_DIR/result-$result_suffix" 2>/dev/null | sort >"/tmp/old-$variant-deps-$$.txt"
+	nix path-info -r "$NEW_DIR/result-$result_suffix" 2>/dev/null | sort >"/tmp/new-$variant-deps-$$.txt"
+
+	# Extract package names
+	while read -r path; do
+		parse_store_path "$path"
+	done <"/tmp/old-$variant-deps-$$.txt" | sort >"/tmp/old-$variant-names-$$.txt"
+
+	while read -r path; do
+		parse_store_path "$path"
+	done <"/tmp/new-$variant-deps-$$.txt" | sort >"/tmp/new-$variant-names-$$.txt"
+
+	# Compare all packages
+	echo "| Package | Old | New | Status |"
+	echo "|---------|-----|-----|--------|"
+
+	# Get all unique package names from both old and new
+	cat "/tmp/old-$variant-names-$$.txt" "/tmp/new-$variant-names-$$.txt" | cut -d' ' -f1 | sort -u | while read -r pkg; do
+		old_match=$(grep "^$pkg " "/tmp/old-$variant-names-$$.txt" | head -1 || echo "")
+		new_match=$(grep "^$pkg " "/tmp/new-$variant-names-$$.txt" | head -1 || echo "")
+
+		if [ -n "$old_match" ] && [ -n "$new_match" ]; then
+			if [ "$old_match" != "$new_match" ]; then
+				# Strip package name prefix to get just the version
+				old_ver="${old_match#"$pkg "}"
+				new_ver="${new_match#"$pkg "}"
+				change_type=$(compare_versions "$old_match" "$new_match")
+				echo "| $pkg | $old_ver | $new_ver | $change_type |"
+
+				# Collect MAJOR updates for summary
+				if [ "$change_type" = "MAJOR" ]; then
+					echo "$CURRENT_PG_VERSION|package|$pkg|$old_ver|$new_ver" >>"$MAJOR_UPDATES_FILE"
+				fi
+			fi
+		elif [ -n "$old_match" ]; then
+			old_ver="${old_match#"$pkg "}"
+			echo "| $pkg | $old_ver | - | REMOVED |"
+		elif [ -n "$new_match" ]; then
+			new_ver="${new_match#"$pkg "}"
+			echo "| $pkg | - | $new_ver | ADDED |"
+		fi
+	done
+
+	echo ""
+	echo "<details>"
+	echo "<summary>Raw Dependency Closure</summary>"
+	echo ""
+	echo "\`\`\`"
+	echo "Old Dependencies:"
+	cat "/tmp/old-$variant-deps-$$.txt"
+	echo ""
+	echo "New Dependencies:"
+	cat "/tmp/new-$variant-deps-$$.txt"
+	echo "\`\`\`"
+	echo ""
+	echo "</details>"
+	echo ""
+}
+
+# Function to generate summary of MAJOR updates
+generate_summary() {
+	if [ ! -s "$MAJOR_UPDATES_FILE" ]; then
+		echo "## Summary"
+		echo ""
+		echo "No packages had MAJOR version updates."
+		echo ""
+	else
+		echo "## Summary"
+		echo ""
+		echo "The following packages underwent **MAJOR** version updates:"
+		echo ""
+		echo "| PostgreSQL Version | Package | Old Version | New Version |"
+		echo "|--------------------|---------|-------------|-------------|"
+
+		while IFS='|' read -r pg_ver _ pkg old_ver new_ver; do
+			echo "| $pg_ver | $pkg | $old_ver | $new_ver |"
+		done <"$MAJOR_UPDATES_FILE"
+
+		echo ""
+	fi
+}
+
+# Redirect analysis output to file (wrap in details/summary for collapsible section)
+{
+	echo "<details>"
+	echo "<summary>Full Analysis Results</summary>"
+	echo ""
+
+	# Analyze all three variants
+	analyze_variant_deps "pg15" "PostgreSQL 15" "psql_15"
+	analyze_variant_deps "pg17" "PostgreSQL 17" "psql_17"
+	analyze_variant_deps "pgorioledb17" "OrioleDB 17" "psql_orioledb-17"
+
+	echo "</details>"
+} >>"$OUTPUT_FILE"
+
+# Generate and insert summary at the top of results
+SUMMARY_CONTENT=$(generate_summary)
+
+# Insert summary after the header but before PostgreSQL version sections
+# We need to insert it after the header (line with "Analysis Date") and before first "##" heading
+if [[ "$OSTYPE" == "darwin"* ]]; then
+	# macOS - create temp file with proper structure
+	{
+		# Read header (including bullet point lines)
+		sed -n '1,/^- \*\*Analysis Date:/p' "$OUTPUT_FILE"
+		echo ""
+		# Insert summary
+		echo "$SUMMARY_CONTENT"
+		# Append rest of file (everything after the header)
+		sed -n '/^- \*\*Analysis Date:/,$p' "$OUTPUT_FILE" | tail -n +2
+	} >"$OUTPUT_FILE.tmp"
+	mv "$OUTPUT_FILE.tmp" "$OUTPUT_FILE"
+else
+	# GNU/Linux - similar approach
+	{
+		sed -n '1,/^- \*\*Analysis Date:/p' "$OUTPUT_FILE"
+		echo ""
+		echo "$SUMMARY_CONTENT"
+		sed -n '/^- \*\*Analysis Date:/,$p' "$OUTPUT_FILE" | tail -n +2
+	} >"$OUTPUT_FILE.tmp"
+	mv "$OUTPUT_FILE.tmp" "$OUTPUT_FILE"
+fi
+
+echo "Analysis complete!"
+echo "Results written to: $OUTPUT_FILE"