diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index ab18585..8d1b547 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -61,9 +61,54 @@ jobs:
         if: inputs.open_gpdb
         run: bash ci/free-disk-space.sh
 
-      - name: Build and install Greenplum
-        if: steps.cache-deps.outputs.cache-hit != 'true'
-        run: bash ci/build-gpdb.sh "${{ inputs.gpdb_repo }}" "${{ inputs.gpdb_ref }}" ${{ inputs.open_gpdb && 'open-gpdb' || '' }}
+      - name: Install Debian packages
+        run: |
+          TARGET_DIR="$HOME/local/gpdb"
+          EXPECTED_SCRIPT="greenplum_path.sh"
+          TEMP_DIR="$HOME/local/gp_temp_install"
+          
+          if [ "${{ inputs.open_gpdb }}" == "true" ]; then
+            PACKAGE_URL="https://github.com/open-gpdb/gpdb/releases/download/6.29.8/greenplum-db-6_6.29.8-1-yandex.54453.5ad8245cbc_amd64.deb"
+            echo "Installing open-gpdb..."
+          else
+            PACKAGE_URL="https://github.com/GreengageDB/greengage/releases/download/6.29.2/greengage6.deb"
+            echo "Installing Greengage..."
+          fi
+
+          mkdir -p "$TEMP_DIR"
+          wget -q "$PACKAGE_URL" -O /tmp/gp.deb
+          sudo apt-get remove -y python-is-python3 || true
+          sudo dpkg -x /tmp/gp.deb "$TEMP_DIR"
+          rm -f /tmp/gp.deb
+
+          REAL_SOURCE=$(find "$TEMP_DIR" -type d -exec test -f {}/"$EXPECTED_SCRIPT" \; -print -quit 2>/dev/null)
+          if [ -z "$REAL_SOURCE" ]; then
+            FOUND_SCRIPT=$(find "$TEMP_DIR" -type f -name "*_path.sh" | head -n 1)
+            [ -n "$FOUND_SCRIPT" ] && REAL_SOURCE=$(dirname "$FOUND_SCRIPT") && EXPECTED_SCRIPT=$(basename "$FOUND_SCRIPT")
+          fi
+
+          if [ -z "$REAL_SOURCE" ]; then
+            echo "ERROR: Installation directory not found" >&2; exit 1
+          fi
+
+          sudo rm -rf "$TARGET_DIR"
+          sudo mv "$REAL_SOURCE" "$TARGET_DIR"
+          sudo rm -rf "$TEMP_DIR"
+
+          sudo chown -R "$USER:$USER" "$TARGET_DIR"
+
+          if [ "$(basename "$EXPECTED_SCRIPT")" != "greenplum_path.sh" ]; then
+             ln -s "$EXPECTED_SCRIPT" "$TARGET_DIR/greenplum_path.sh"
+          fi
+
+          source "$TARGET_DIR/greenplum_path.sh"
+          echo "Greenplum ready at: $GPHOME"
+
+      - name: Build and install Arrow 15
+        run: bash ci/build-arrow.sh
+
+      - name: Build and install gRPC
+        run: bash ci/build-grpc.sh
 
       - name: Build and install Arrow 15
         if: steps.cache-deps.outputs.cache-hit != 'true'
@@ -73,10 +118,6 @@ jobs:
         if: steps.cache-deps.outputs.cache-hit != 'true'
         run: bash ci/build-grpc.sh
 
-      - name: Verify open-gpdb defines OPENGPDB
-        if: inputs.open_gpdb
-        run: bash ci/verify-opengpdb-define.sh
-
       - name: Build Tea
         run: bash ci/build-tea.sh
 
diff --git a/ci/build-gpdb.sh b/ci/build-gpdb.sh
deleted file mode 100644
index c64e8ad..0000000
--- a/ci/build-gpdb.sh
+++ /dev/null
@@ -1,52 +0,0 @@
-#!/usr/bin/env bash
-# Build and install Greenplum 6 into $HOME/local/gpdb.
-#
-# Usage: build-gpdb.sh <repo-url> <ref> [open-gpdb]
-#
-# Passing "open-gpdb" as the third argument enables the fixups needed for the
-# open-gpdb fork (see the inline comments below); arenadata/gpdb builds without
-# them.
-set -eo pipefail
-
-repo="$1"
-ref="$2"
-mode="${3:-}"
-
-git clone "$repo" -b "$ref" --depth 1 gpdb
-cd gpdb
-git submodule update --init
-
-configure_extra=()
-if [ "$mode" = "open-gpdb" ]; then
-  # ORCA in open-gpdb still builds with -std=c++98/gnu++98, but the system
-  # Xerces-C 3.2 (Ubuntu 22.04) requires C++11 (char16_t); bump the ORCA C++
-  # standard to gnu++14 (gnu++17 would reject ORCA's deprecated throw() specs).
-  # gnu++14 + -Wextra then surfaces -Wdeprecated-copy / -Wnonnull-compare which
-  # ORCA's -Werror turns fatal, so append -Wno-error=... last (wins over it).
-  for mk in src/backend/gpopt/gpopt.mk \
-            src/backend/gporca/gporca.mk \
-            src/backend/gporca/libgpos/src/common/Makefile; do
-    sed -i 's/-std=gnu++98/-std=gnu++14/g; s/-std=c++98/-std=gnu++14/g' "$mk"
-    printf '\noverride CPPFLAGS := $(CPPFLAGS) -Wno-error=deprecated-copy -Wno-error=nonnull-compare\n' >> "$mk"
-  done
-  # open-gpdb defaults --with-mdblocales=yes and hard-requires the mdblocales
-  # lib/header, which is not available on the CI image.
-  configure_extra+=(--without-mdblocales)
-fi
-
-# TODO(gmusya): consider using --enable-cassert
-./configure --with-perl --with-python --with-libxml --with-gssapi \
-  --with-pythonsrc-ext "${configure_extra[@]}" --prefix="$HOME/local/gpdb"
-
-if [ "$mode" = "open-gpdb" ]; then
-  # src/common (FRONTEND) includes the backend-generated utils/errcodes.h but
-  # has no order-only dep on it, so -j8 races ("errcodes.h: No such file").
-  # Force the generated header first.
-  make -C src/backend submake-errcodes
-fi
-
-make -j8
-make -j8 install
-
-cd ..
-rm -rf gpdb
diff --git a/ci/verify-opengpdb-define.sh b/ci/verify-opengpdb-define.sh
deleted file mode 100644
index 53d490c..0000000
--- a/ci/verify-opengpdb-define.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/usr/bin/env bash
-# tea relies on the OPENGPDB macro (defined in pg_config_manual.h) to select
-# the open-gpdb sampling API; make sure the freshly built gpdb defines it.
-set -ex
-
-grep -q '#define OPENGPDB' \
-  "$HOME/local/gpdb/include/postgresql/server/pg_config_manual.h"