feat(仪表盘): 引入预聚合统计与聚合作业

backend/migrations/035_usage_logs_partitioning.sql

@@ -0,0 +1,54 @@
+-- usage_logs monthly partition bootstrap.
+-- Only converts to partitioned table when usage_logs is empty.
+-- Existing installations with data require a manual migration plan.
+
+DO $$
+DECLARE
+    is_partitioned BOOLEAN := FALSE;
+    has_data BOOLEAN := FALSE;
+    month_start DATE;
+    prev_month DATE;
+    next_month DATE;
+BEGIN
+    SELECT EXISTS(
+        SELECT 1
+        FROM pg_partitioned_table pt
+        JOIN pg_class c ON c.oid = pt.partrelid
+        WHERE c.relname = 'usage_logs'
+    ) INTO is_partitioned;
+
+    IF NOT is_partitioned THEN
+        SELECT EXISTS(SELECT 1 FROM usage_logs LIMIT 1) INTO has_data;
+        IF NOT has_data THEN
+            EXECUTE 'ALTER TABLE usage_logs PARTITION BY RANGE (created_at)';
+            is_partitioned := TRUE;
+        END IF;
+    END IF;
+
+    IF is_partitioned THEN
+        month_start := date_trunc('month', now() AT TIME ZONE 'UTC')::date;
+        prev_month := (month_start - INTERVAL '1 month')::date;
+        next_month := (month_start + INTERVAL '1 month')::date;
+
+        EXECUTE format(
+            'CREATE TABLE IF NOT EXISTS usage_logs_%s PARTITION OF usage_logs FOR VALUES FROM (%L) TO (%L)',
+            to_char(prev_month, 'YYYYMM'),
+            prev_month,
+            month_start
+        );
+
+        EXECUTE format(
+            'CREATE TABLE IF NOT EXISTS usage_logs_%s PARTITION OF usage_logs FOR VALUES FROM (%L) TO (%L)',
+            to_char(month_start, 'YYYYMM'),
+            month_start,
+            next_month
+        );
+
+        EXECUTE format(
+            'CREATE TABLE IF NOT EXISTS usage_logs_%s PARTITION OF usage_logs FOR VALUES FROM (%L) TO (%L)',
+            to_char(next_month, 'YYYYMM'),
+            next_month,
+            (next_month + INTERVAL '1 month')::date
+        );
+    END IF;
+END $$;