diff --git a/nexus/db-queries/src/db/datastore/clickhouse_policy.rs b/nexus/db-queries/src/db/datastore/clickhouse_policy.rs
index 0d7fb0af2c..f79c57687f 100644
--- a/nexus/db-queries/src/db/datastore/clickhouse_policy.rs
+++ b/nexus/db-queries/src/db/datastore/clickhouse_policy.rs
@@ -95,30 +95,7 @@ impl DataStore {
         let num_inserted = if policy.version == 1 {
             self.clickhouse_policy_insert_first_policy(opctx, &policy).await?
         } else {
-            let prev_version = policy.version - 1;
-
-            sql_query(
-                r"INSERT INTO clickhouse_policy 
-                 (version, clickhouse_mode, clickhouse_cluster_target_servers, 
-                  clickhouse_cluster_target_keepers, time_created) 
-                 SELECT $1, $2, $3, $4, $5 
-                  FROM clickhouse_policy WHERE version = $6 AND version IN
-                   (SELECT version FROM clickhouse_policy
-                    ORDER BY version DESC LIMIT 1)",
-            )
-            .bind::<sql_types::BigInt, SqlU32>(policy.version.into())
-            .bind::<ClickhouseModeEnum, DbClickhouseMode>((&policy.mode).into())
-            .bind::<sql_types::SmallInt, SqlU8>(
-                policy.mode.target_servers().into(),
-            )
-            .bind::<sql_types::SmallInt, SqlU8>(
-                policy.mode.target_keepers().into(),
-            )
-            .bind::<sql_types::Timestamptz, _>(policy.time_created)
-            .bind::<sql_types::BigInt, SqlU32>(prev_version.into())
-            .execute_async(&*self.pool_connection_authorized(opctx).await?)
-            .await
-            .map_err(|e| public_error_from_diesel(e, ErrorHandler::Server))?
+            self.clickhouse_policy_insert_next_policy(opctx, &policy).await?
         };
 
         match num_inserted {
@@ -133,6 +110,40 @@ impl DataStore {
         }
     }
 
+    /// Insert the next version of the policy in the database
+    ///
+    /// Only succeeds if the prior version is the latest version currently
+    /// in the `clickhouse_policy` table.
+    ///
+    /// Panics if `policy.version <= 1`;
+    async fn clickhouse_policy_insert_next_policy(
+        &self,
+        opctx: &OpContext,
+        policy: &ClickhousePolicy,
+    ) -> Result<usize, Error> {
+        assert!(policy.version > 1);
+        let prev_version = policy.version - 1;
+
+        sql_query(
+            r"INSERT INTO clickhouse_policy
+                 (version, clickhouse_mode, clickhouse_cluster_target_servers,
+                  clickhouse_cluster_target_keepers, time_created)
+                 SELECT $1, $2, $3, $4, $5
+                  FROM clickhouse_policy WHERE version = $6 AND version IN
+                   (SELECT version FROM clickhouse_policy
+                    ORDER BY version DESC LIMIT 1)",
+        )
+        .bind::<sql_types::BigInt, SqlU32>(policy.version.into())
+        .bind::<ClickhouseModeEnum, DbClickhouseMode>((&policy.mode).into())
+        .bind::<sql_types::SmallInt, SqlU8>(policy.mode.target_servers().into())
+        .bind::<sql_types::SmallInt, SqlU8>(policy.mode.target_keepers().into())
+        .bind::<sql_types::Timestamptz, _>(policy.time_created)
+        .bind::<sql_types::BigInt, SqlU32>(prev_version.into())
+        .execute_async(&*self.pool_connection_authorized(opctx).await?)
+        .await
+        .map_err(|e| public_error_from_diesel(e, ErrorHandler::Server))
+    }
+
     /// Insert the first clickhouse policy in the database at version 1.
     ///
     /// Only insert this policy if no other policy exists yet.
@@ -144,10 +155,10 @@ impl DataStore {
         policy: &ClickhousePolicy,
     ) -> Result<usize, Error> {
         sql_query(
-            r"INSERT INTO clickhouse_policy 
-              (version, clickhouse_mode, clickhouse_cluster_target_servers, 
-               clickhouse_cluster_target_keepers, time_created) 
-             SELECT $1, $2, $3, $4, $5 
+            r"INSERT INTO clickhouse_policy
+              (version, clickhouse_mode, clickhouse_cluster_target_servers,
+               clickhouse_cluster_target_keepers, time_created)
+             SELECT $1, $2, $3, $4, $5
              WHERE NOT EXISTS (SELECT * FROM clickhouse_policy)",
         )
         .bind::<sql_types::BigInt, SqlU32>(policy.version.into())
diff --git a/nexus/types/src/deployment/planning_input.rs b/nexus/types/src/deployment/planning_input.rs
index 6201abb921..741cf3b539 100644
--- a/nexus/types/src/deployment/planning_input.rs
+++ b/nexus/types/src/deployment/planning_input.rs
@@ -125,18 +125,12 @@ impl PlanningInput {
     }
 
     pub fn target_clickhouse_zone_count(&self) -> usize {
-        if let Some(policy) = &self.policy.clickhouse_policy {
-            match policy.mode {
-                ClickhouseMode::SingleNodeOnly => {
-                    SINGLE_NODE_CLICKHOUSE_REDUNDANCY
-                }
-                ClickhouseMode::ClusterOnly { .. } => 0,
-                ClickhouseMode::Both { .. } => {
-                    SINGLE_NODE_CLICKHOUSE_REDUNDANCY
-                }
-            }
-        } else {
-            SINGLE_NODE_CLICKHOUSE_REDUNDANCY
+        match self.policy.clickhouse_policy.as_ref().map(|policy| &policy.mode)
+        {
+            Some(&ClickhouseMode::ClusterOnly { .. }) => 0,
+            Some(&ClickhouseMode::SingleNodeOnly)
+            | Some(&ClickhouseMode::Both { .. })
+            | None => SINGLE_NODE_CLICKHOUSE_REDUNDANCY,
         }
     }
 
@@ -144,7 +138,7 @@ impl PlanningInput {
         self.policy
             .clickhouse_policy
             .as_ref()
-            .map(|policy| policy.mode.target_servers() as usize)
+            .map(|policy| usize::from(policy.mode.target_servers()))
             .unwrap_or(0)
     }
 
@@ -152,7 +146,7 @@ impl PlanningInput {
         self.policy
             .clickhouse_policy
             .as_ref()
-            .map(|policy| policy.mode.target_keepers() as usize)
+            .map(|policy| usize::from(policy.mode.target_keepers()))
             .unwrap_or(0)
     }
 
@@ -912,14 +906,17 @@ impl ClickhouseMode {
     pub fn cluster_enabled(&self) -> bool {
         match self {
             ClickhouseMode::SingleNodeOnly => false,
-            _ => true,
+            ClickhouseMode::ClusterOnly { .. }
+            | ClickhouseMode::Both { .. } => true,
         }
     }
 
     pub fn single_node_enabled(&self) -> bool {
         match self {
             ClickhouseMode::ClusterOnly { .. } => false,
-            _ => true,
+            ClickhouseMode::SingleNodeOnly | ClickhouseMode::Both { .. } => {
+                true
+            }
         }
     }