diff --git a/src/app/(dashboard)/dashboard/analytics/ComboHealthTab.tsx b/src/app/(dashboard)/dashboard/analytics/ComboHealthTab.tsx
index 6096b6c8f9..3455c296c4 100644
--- a/src/app/(dashboard)/dashboard/analytics/ComboHealthTab.tsx
+++ b/src/app/(dashboard)/dashboard/analytics/ComboHealthTab.tsx
@@ -295,51 +295,15 @@ export default function ComboHealthTab() {
   const [error, setError] = useState<string | null>(null);
   const [retrying, setRetrying] = useState(false);
 
-  useEffect(() => {
-    const controller = new AbortController();
-
-    async function fetchComboHealth() {
-      setLoading(true);
+  const fetchData = useCallback(
+    async (controller: AbortController, isRetry = false) => {
+      if (isRetry) {
+        setRetrying(true);
+      } else {
+        setLoading(true);
+      }
       setError(null);
 
-      try {
-        const response = await fetch(`/api/usage/combo-health?range=${range}`, {
-          signal: controller.signal,
-        });
-
-        if (!response.ok) {
-          throw new Error("Failed to fetch combo health data");
-        }
-
-        const result = (await response.json()) as ComboHealthResponse;
-        setData(result);
-      } catch (fetchError) {
-        if ((fetchError as Error).name === "AbortError") {
-          return;
-        }
-
-        setError(fetchError instanceof Error ? fetchError.message : "Unknown error");
-        setData(null);
-      } finally {
-        if (!controller.signal.aborted) {
-          setLoading(false);
-        }
-      }
-    }
-
-    fetchComboHealth();
-
-    return () => controller.abort();
-  }, [range]);
-
-  const combos = data?.combos ?? [];
-
-  const handleRetry = useCallback(() => {
-    setRetrying(true);
-    setError(null);
-    const controller = new AbortController();
-
-    async function retryFetch() {
       try {
         const response = await fetch(`/api/usage/combo-health?range=${range}`, {
           signal: controller.signal,
@@ -357,18 +321,29 @@ export default function ComboHealthTab() {
           return;
         }
         setError(fetchError instanceof Error ? fetchError.message : "Unknown error");
+        if (!isRetry) setData(null);
       } finally {
         if (!controller.signal.aborted) {
           setLoading(false);
-          setRetrying(false);
+          if (isRetry) setRetrying(false);
         }
       }
-    }
-
-    retryFetch();
+    },
+    [range]
+  );
 
+  useEffect(() => {
+    const controller = new AbortController();
+    fetchData(controller, false);
     return () => controller.abort();
-  }, [range]);
+  }, [fetchData]);
+
+  const combos = data?.combos ?? [];
+
+  const handleRetry = useCallback(() => {
+    const controller = new AbortController();
+    fetchData(controller, true);
+  }, [fetchData]);
 
   return (
     <div className="flex flex-col gap-6">
diff --git a/src/lib/db/migrations/012_quota_snapshots.sql b/src/lib/db/migrations/013_quota_snapshots.sql
similarity index 96%
rename from src/lib/db/migrations/012_quota_snapshots.sql
rename to src/lib/db/migrations/013_quota_snapshots.sql
index d655405e26..0843b42cde 100644
--- a/src/lib/db/migrations/012_quota_snapshots.sql
+++ b/src/lib/db/migrations/013_quota_snapshots.sql
@@ -1,4 +1,4 @@
--- 012_quota_snapshots.sql
+-- 013_quota_snapshots.sql
 -- Quota snapshots for subscription utilization tracking.
 -- Stores periodic snapshots of quota state for historical analysis and time-series queries.
 
diff --git a/src/lib/db/quotaSnapshots.ts b/src/lib/db/quotaSnapshots.ts
index 09d0203e13..49cfd8a582 100644
--- a/src/lib/db/quotaSnapshots.ts
+++ b/src/lib/db/quotaSnapshots.ts
@@ -87,7 +87,11 @@ export function getAggregatedSnapshots(opts: {
     params.push(opts.until);
   }
 
-  const bucketSeconds = opts.bucketMinutes * 60;
+  const bucketSeconds = Number(opts.bucketMinutes) * 60;
+  if (!Number.isFinite(bucketSeconds) || bucketSeconds <= 0) {
+    throw new Error("Invalid bucket size");
+  }
+
   const sql = `
     SELECT 
       datetime((strftime('%s', created_at) / ${bucketSeconds}) * ${bucketSeconds}, 'unixepoch') as bucket,
diff --git a/src/shared/components/analytics/TimeRangeSelector.tsx b/src/shared/components/analytics/TimeRangeSelector.tsx
index 49588b3238..0dcba97437 100644
--- a/src/shared/components/analytics/TimeRangeSelector.tsx
+++ b/src/shared/components/analytics/TimeRangeSelector.tsx
@@ -19,7 +19,7 @@ export default function TimeRangeSelector({ value, onChange }: TimeRangeSelector
   return (
     <div
       role="tablist"
-      aria-label="시간 범위 선택"
+      aria-label="Select time range"
       className="inline-flex items-center gap-1 rounded-lg bg-black/5 p-1 dark:bg-white/5"
     >
       {OPTIONS.map((option) => {