diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 796445bb..dbed1f6f 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -3,34 +3,74 @@ name: Build
 on:
   push:
     branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
 jobs:
   build:
-    runs-on: self-hosted  # or `ubuntu-22.04`
+    # This fork has no self-hosted runners. Upstream's self-hosted pool is
+    # private, so jobs there sit in action_required. Use GitHub-hosted 22.04
+    # to match the documented toolchain (clang-14, gcc-12, libprocps-dev).
+    runs-on: ubuntu-22.04
+    timeout-minutes: 180
 
     steps:
     - uses: actions/checkout@v4
 
-    - name: Configure sccache-cache
+    - name: Free disk space
       run: |
-        echo "RUSTC_WRAPPER=sccache" >> $GITHUB_ENV
-        echo "SCCACHE_GHA_ENABLED=true" >> $GITHUB_ENV
-
-    - name: Run sccache-cache
-      uses: mozilla-actions/sccache-action@v0.0.4
+        sudo rm -rf /usr/share/dotnet /usr/local/lib/android /opt/ghc \
+          /opt/hostedtoolcache/CodeQL /usr/local/share/powershell \
+          /usr/share/swift
+        df -h
 
     - name: Prepare
       run: |
-        sudo apt install -y cmake libuv1-dev liblz4-dev liblzma-dev libdouble-conversion-dev libprocps-dev libdwarf-dev libunwind-dev
-        sudo apt install -y libaio-dev libgflags-dev libgoogle-glog-dev libgtest-dev libgmock-dev clang-format-14 clang-14 clang-tidy-14 lld-14
-        sudo apt install -y libgoogle-perftools-dev google-perftools libssl-dev ccache gcc-12 g++-12 libboost-all-dev meson rustc cargo
-        wget https://github.com/apple/foundationdb/releases/download/7.1.61/foundationdb-clients_7.1.61-1_amd64.deb && sudo dpkg -i foundationdb-clients_7.1.61-1_amd64.deb
-        git clone https://github.com/libfuse/libfuse.git libfuse -b fuse-3.16.2 --depth 1 && mkdir libfuse/build && cd libfuse/build && meson setup .. && ninja && sudo ninja install && cd ../.. && rm -rf libfuse
+        sudo apt-get update
+        sudo DEBIAN_FRONTEND=noninteractive apt-get install -y \
+          cmake ninja-build meson pkg-config wget build-essential \
+          libuv1-dev liblz4-dev liblzma-dev libdouble-conversion-dev \
+          libprocps-dev libdwarf-dev libunwind-dev libaio-dev \
+          libgflags-dev libgoogle-glog-dev libgtest-dev libgmock-dev \
+          clang-format-14 clang-14 clang-tidy-14 lld-14 \
+          libgoogle-perftools-dev google-perftools libssl-dev ccache \
+          gcc-12 g++-12 libboost-all-dev rustc cargo \
+          libibverbs-dev libnuma-dev python3-dev
+        wget -q https://github.com/apple/foundationdb/releases/download/7.1.61/foundationdb-clients_7.1.61-1_amd64.deb
+        sudo dpkg -i foundationdb-clients_7.1.61-1_amd64.deb
+        git clone https://github.com/libfuse/libfuse.git libfuse -b fuse-3.16.2 --depth 1
+        cmake -E make_directory libfuse/build
+        CC=clang-14 CXX=clang++-14 meson setup libfuse/build libfuse
+        ninja -C libfuse/build
+        sudo ninja -C libfuse/build install
+        rm -rf libfuse
         git submodule update --init --recursive
         ./patches/apply.sh
 
+    # 16GB hosted runners OOM when Arrow + Folly + RocksDB compile together.
+    # /swapfile is already active on ubuntu-22.04 runners ("Text file busy").
+    - name: Enable extra swap
+      run: |
+        sudo rm -f /swapfile.ci
+        sudo fallocate -l 8G /swapfile.ci
+        sudo chmod 600 /swapfile.ci
+        sudo mkswap /swapfile.ci
+        sudo swapon /swapfile.ci
+        free -h
+
     - name: Build
+      env:
+        CMAKE_BUILD_PARALLEL_LEVEL: 2
+        CARGO_BUILD_JOBS: 2
       run: |
         cargo build --release
-        cmake -S . -B build -DCMAKE_CXX_COMPILER=clang++-14 -DCMAKE_C_COMPILER=clang-14 -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
-        cmake --build build -j 32
+        cmake -S . -B build \
+          -DCMAKE_CXX_COMPILER=clang++-14 \
+          -DCMAKE_C_COMPILER=clang-14 \
+          -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+          -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
+        cmake --build build --parallel 2
diff --git a/cmake/ApacheArrow.cmake b/cmake/ApacheArrow.cmake
index 42da824f..610944f0 100644
--- a/cmake/ApacheArrow.cmake
+++ b/cmake/ApacheArrow.cmake
@@ -36,7 +36,7 @@ ExternalProject_Add(
         -DARROW_BUILD_EXAMPLES=OFF \
         -DARROW_PARQUET=ON -DARROW_CSV=ON \
         -DARROW_WITH_ZSTD=ON -DARROW_WITH_LZ4=ON -DARROW_WITH_ZLIB=ON"
-    BUILD_COMMAND bash -x -c "source thirdparty/export.sh && cmake --build . -j"
+    BUILD_COMMAND bash -x -c "source thirdparty/export.sh && cmake --build . -j \${CMAKE_BUILD_PARALLEL_LEVEL:-2}"
     INSTALL_COMMAND cmake --install . --prefix "${PREFIX}"
     BUILD_BYPRODUCTS
         "${ARROW_RELEASE_BUILD_DIR}/libarrow.a"