diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index e588a9d279d..d27ed6515dc 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -108,7 +108,7 @@ jobs:
       # actions/cache@v2.1.4
       uses: actions/cache@26968a09c0ea4f3e233fdddbafd1166051a095f6
       with:
-        key: ${{ runner.os }}-clickhouse-binary-${{ hashFiles('tools/clickhouse_checksums') }}
+        key: ${{ runner.os }}-clickhouse-binary-${{ hashFiles('tools/clickhouse_versions') }}
         path: "clickhouse"
     - name: Download ClickHouse
       if: steps.cache-clickhouse.outputs.cache-hit != 'true'
diff --git a/tools/ci_download_clickhouse b/tools/ci_download_clickhouse
index c1099216941..215b7724221 100755
--- a/tools/ci_download_clickhouse
+++ b/tools/ci_download_clickhouse
@@ -13,14 +13,30 @@ set -o errexit
 SOURCE_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
 ARG0="$(basename ${BASH_SOURCE[0]})"
 
-# If you change this, you must also update the md5sums below
-CIDL_VERSION="v21.7"
-source "$SOURCE_DIR/clickhouse_checksums"
+CIDL_VERSION_FILE="$SOURCE_DIR/clickhouse_versions"
+source "$CIDL_VERSION_FILE"
 CIDL_ASSEMBLE_DIR="./clickhouse"
 
 # Download from manually-populated S3 bucket for now
 CIDL_URL_BASE="https://oxide-clickhouse-build.s3.us-west-2.amazonaws.com"
 
+function per_platform
+{
+	#
+	# We should use "${1^^}" here instead of tr(1), except that Apple, in a
+	# thoroughly characteristic fit of user hostility, ship a flagrantly
+	# obsolete version of bash that has no features.
+	#
+	local pp_key="$(tr '[:lower:]' '[:upper:]' <<< "$1")"
+	local pp_platform="$(tr '[:lower:]' '[:upper:]' <<< "$2")"
+	local pp_varname="CIDL_${pp_key}_${pp_platform}"
+	local pp_val="${!pp_varname}"
+	if [[ -z "$pp_val" ]]; then
+		fail "missing \"$pp_varname\" in \"$CIDL_VERSION_FILE\""
+	fi
+	printf '%s' "$pp_val"
+}
+
 function main
 {
 	#
@@ -44,18 +60,42 @@ function main
 	configure_os "$CIDL_OS"
 	CIDL_URL="$CIDL_URL_BASE/$CIDL_FILE"
 
-	# Download the file.
 	echo "URL: $CIDL_URL"
 	echo "Local file: $CIDL_FILE"
-	do_download_curl "$CIDL_URL" "$CIDL_FILE" || \
-	    fail "failed to download file"
-
-	# Verify the md5sum.
-	calculated_md5="$($CIDL_MD5FUNC "$CIDL_FILE")" || \
-	    fail "failed to calculate md5sum"
-	if [[ "$calculated_md5" != "$CIDL_MD5" ]]; then
-		fail "md5sum mismatch \
-		    (expected $CIDL_MD5, found $calculated_md5)"
+
+	#
+	# If the file exists already, check to see if the hash matches so that
+	# we can avoid a second download.
+	#
+	if [[ -f "$CIDL_FILE" ]]; then
+		calculated_md5="$($CIDL_MD5FUNC "$CIDL_FILE")" || \
+		    fail "failed to calculate md5sum"
+		if [[ "$calculated_md5" == "$CIDL_MD5" ]]; then
+			download=no
+		else
+			rm -f "$CIDL_FILE"
+			download=yes
+		fi
+	else
+		download=yes
+	fi
+
+	if [[ "$download" == yes ]]; then
+		#
+		# Download the file.
+		#
+		do_download_curl "$CIDL_URL" "$CIDL_FILE" || \
+		    fail "failed to download file"
+
+		#
+		# Verify the md5sum.
+		#
+		calculated_md5="$($CIDL_MD5FUNC "$CIDL_FILE")" || \
+		    fail "failed to calculate md5sum"
+		if [[ "$calculated_md5" != "$CIDL_MD5" ]]; then
+			fail "md5sum mismatch \
+			    (expected $CIDL_MD5, found $calculated_md5)"
+		fi
 	fi
 
 	# Unpack the tarball into a local directory
@@ -76,27 +116,29 @@ function configure_os
 	echo "current directory: $PWD"
 	echo "configuring based on OS: \"$1\""
 	case "$1" in
-		darwin*)
-            CIDL_PLATFORM="macos"
-			CIDL_MD5="$CIDL_MD5_DARWIN"
-			CIDL_MD5FUNC="do_md5"
-			;;
-		linux-gnu*) 
-            CIDL_PLATFORM="linux"
-			CIDL_MD5="$CIDL_MD5_LINUX"
-			CIDL_MD5FUNC="do_md5sum"
-			;;
-		solaris*)
-            CIDL_PLATFORM="illumos"
-			CIDL_MD5="$CIDL_MD5_ILLUMOS"
-			CIDL_MD5FUNC="do_md5sum"
-			;;
-		*)
-			fail "unsupported OS: $1"
-			;;
+	darwin*)
+		CIDL_PLATFORM="macos"
+		CIDL_MD5FUNC="do_md5"
+		;;
+	linux-gnu*)
+		CIDL_PLATFORM="linux"
+		CIDL_MD5FUNC="do_md5sum"
+		;;
+	solaris*)
+		CIDL_PLATFORM="illumos"
+		CIDL_MD5FUNC="do_md5sum"
+		;;
+	*)
+		fail "unsupported OS: $1"
+		;;
 	esac
 
-	CIDL_DIR="clickhouse-$CIDL_VERSION"
+	if ! CIDL_VERSION=$(per_platform version "$CIDL_PLATFORM") ||
+	    ! CIDL_MD5=$(per_platform md5 "$CIDL_PLATFORM"); then
+		fail "could not configure platform $CIDL_PLATFORM"
+	fi
+
+	CIDL_DIR="clickhouse-v$CIDL_VERSION"
 	CIDL_FILE="$CIDL_DIR.$CIDL_PLATFORM.tar.gz"
 }
 
diff --git a/tools/clickhouse_checksums b/tools/clickhouse_checksums
deleted file mode 100644
index 2eb9636de5e..00000000000
--- a/tools/clickhouse_checksums
+++ /dev/null
@@ -1,3 +0,0 @@
-CIDL_MD5_DARWIN="7e22bd0b0108dee55605dd563a5698df"
-CIDL_MD5_LINUX="f821613422cda8bb3c7f281eeb87f145"
-CIDL_MD5_ILLUMOS="2870157143dc78b1ebe1e3dfabe5fd61"
diff --git a/tools/clickhouse_versions b/tools/clickhouse_versions
new file mode 100644
index 00000000000..6efc5848426
--- /dev/null
+++ b/tools/clickhouse_versions
@@ -0,0 +1,8 @@
+CIDL_VERSION_ILLUMOS="21.10.4.26"
+CIDL_MD5_ILLUMOS="d2ff9c8d15d017a76a605a33618b9da4"
+
+CIDL_VERSION_LINUX="21.10.4.26"
+CIDL_MD5_LINUX="7aa1e2eb55d7540ab71fde2e4abb4c81"
+
+CIDL_VERSION_MACOS="21.7"
+CIDL_MD5_MACOS="7e22bd0b0108dee55605dd563a5698df"