improve aggregation logic

internal/report/snapshots.go

@@ -664,6 +664,21 @@ func validateTableName(name string) error {
 	return nil
 }
 
+func tableHasRows(ctx context.Context, dbConn *sqlx.DB, table string) (bool, error) {
+	if err := validateTableName(table); err != nil {
+		return false, err
+	}
+	query := fmt.Sprintf(`SELECT 1 FROM %s LIMIT 1`, table)
+	var exists int
+	if err := dbConn.GetContext(ctx, &exists, query); err != nil {
+		if err == sql.ErrNoRows {
+			return false, nil
+		}
+		return false, err
+	}
+	return true, nil
+}
+
 func tableColumns(ctx context.Context, dbConn *sqlx.DB, tableName string) ([]string, error) {
 	driver := strings.ToLower(dbConn.DriverName())
 	switch driver {
@@ -908,6 +923,9 @@ func buildHourlyTotals(ctx context.Context, dbConn *sqlx.DB, records []SnapshotR
 		if err := validateTableName(record.TableName); err != nil {
 			return nil, err
 		}
+		if rowsExist, err := tableHasRows(ctx, dbConn, record.TableName); err != nil || !rowsExist {
+			continue
+		}
 		query := fmt.Sprintf(`
 SELECT
   COUNT(DISTINCT "VmId") AS vm_count,
@@ -955,6 +973,9 @@ func buildDailyTotals(ctx context.Context, dbConn *sqlx.DB, records []SnapshotRe
 		if err := validateTableName(record.TableName); err != nil {
 			return nil, err
 		}
+		if rowsExist, err := tableHasRows(ctx, dbConn, record.TableName); err != nil || !rowsExist {
+			continue
+		}
 		query := fmt.Sprintf(`
 SELECT
   COUNT(DISTINCT "VmId") AS vm_count,

internal/tasks/inventorySnapshots.go

@@ -170,6 +170,7 @@ func (c *CronTask) aggregateDailySummary(ctx context.Context, targetTime time.Ti
 	if err != nil {
 		return err
 	}
+	hourlySnapshots = filterSnapshotsWithRows(ctx, dbConn, hourlySnapshots)
 	if len(hourlySnapshots) == 0 {
 		return fmt.Errorf("no hourly snapshot tables found for %s", dayStart.Format("2006-01-02"))
 	}
@@ -202,6 +203,7 @@ func (c *CronTask) aggregateDailySummary(ctx context.Context, targetTime time.Ti
 	prevEnd := dayStart
 	prevSnapshots, err := report.ListSnapshotsByRange(ctx, c.Database, "hourly", prevStart, prevEnd)
 	if err == nil && len(prevSnapshots) > 0 {
+		prevSnapshots = filterSnapshotsWithRows(ctx, dbConn, prevSnapshots)
 		prevTables := make([]string, 0, len(prevSnapshots))
 		for _, snapshot := range prevSnapshots {
 			prevTables = append(prevTables, snapshot.TableName)
@@ -228,6 +230,9 @@ func (c *CronTask) aggregateDailySummary(ctx context.Context, targetTime time.Ti
 	}
 
 	insertQuery := fmt.Sprintf(`
+WITH snapshots AS (
+%s
+)
 INSERT INTO %s (
   "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId", "CreationTime", "DeletionTime",
   "ResourcePool", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
@@ -240,7 +245,16 @@ SELECT
   "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId",
   COALESCE(NULLIF("CreationTime", 0), MIN(CASE WHEN "IsPresent" = 'TRUE' THEN "SnapshotTime" END), 0) AS "CreationTime",
   "DeletionTime",
-  "ResourcePool", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
+  (
+    SELECT s2."ResourcePool"
+    FROM snapshots s2
+    WHERE s2."VmId" = snapshots."VmId"
+      AND s2."Vcenter" = snapshots."Vcenter"
+      AND s2."IsPresent" = 'TRUE'
+    ORDER BY s2."SnapshotTime" DESC
+    LIMIT 1
+  ) AS "ResourcePool",
+  "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
   "RamGB", "IsTemplate", "PoweredOn", "SrmPlaceholder", "VmUuid",
   SUM(CASE WHEN "IsPresent" = 'TRUE' THEN 1 ELSE 0 END) AS "SamplesPresent",
   AVG(CASE WHEN "IsPresent" = 'TRUE' AND "VcpuCount" IS NOT NULL THEN "VcpuCount" END) AS "AvgVcpuCount",
@@ -263,14 +277,12 @@ SELECT
     / NULLIF(SUM(CASE WHEN "IsPresent" = 'TRUE' THEN 1 ELSE 0 END), 0) AS "Silver",
   100.0 * SUM(CASE WHEN "IsPresent" = 'TRUE' AND LOWER("ResourcePool") = 'gold' THEN 1 ELSE 0 END)
     / NULLIF(SUM(CASE WHEN "IsPresent" = 'TRUE' THEN 1 ELSE 0 END), 0) AS "Gold"
-FROM (
+FROM snapshots
-%s
-) snapshots
 GROUP BY
   "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId", "CreationTime", "DeletionTime",
-  "ResourcePool", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
+  "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
   "RamGB", "IsTemplate", "PoweredOn", "SrmPlaceholder", "VmUuid";
-`, summaryTable, unionQuery)
+`, unionQuery, summaryTable)
 
 	if _, err := dbConn.ExecContext(ctx, insertQuery); err != nil {
 		c.Logger.Error("failed to aggregate daily inventory", "error", err, "date", dayStart.Format("2006-01-02"))
@@ -311,6 +323,9 @@ func (c *CronTask) aggregateMonthlySummary(ctx context.Context, targetMonth time
 	if err != nil {
 		return err
 	}
+
+	dbConn := c.Database.DB()
+	dailySnapshots = filterSnapshotsWithRows(ctx, dbConn, dailySnapshots)
 	if len(dailySnapshots) == 0 {
 		return fmt.Errorf("no hourly snapshot tables found for %s", targetMonth.Format("2006-01"))
 	}
@@ -320,7 +335,6 @@ func (c *CronTask) aggregateMonthlySummary(ctx context.Context, targetMonth time
 		return err
 	}
 
-	dbConn := c.Database.DB()
 	if err := ensureMonthlySummaryTable(ctx, dbConn, monthlyTable); err != nil {
 		return err
 	}
@@ -349,7 +363,7 @@ func (c *CronTask) aggregateMonthlySummary(ctx context.Context, targetMonth time
 		`"InventoryId"`, `"Name"`, `"Vcenter"`, `"VmId"`, `"EventKey"`, `"CloudId"`, `"CreationTime"`,
 		`"DeletionTime"`, `"ResourcePool"`, `"Datacenter"`, `"Cluster"`, `"Folder"`,
 		`"ProvisionedDisk"`, `"VcpuCount"`, `"RamGB"`, `"IsTemplate"`, `"PoweredOn"`,
-		`"SrmPlaceholder"`, `"VmUuid"`, `"IsPresent"`,
+		`"SrmPlaceholder"`, `"VmUuid"`, `"SnapshotTime"`, `"IsPresent"`,
 	}, templateExclusionFilter())
 	if strings.TrimSpace(unionQuery) == "" {
 		return fmt.Errorf("no valid daily snapshot tables found for %s", targetMonth.Format("2006-01"))
@@ -369,6 +383,9 @@ func (c *CronTask) aggregateMonthlySummary(ctx context.Context, targetMonth time
 	}
 
 	insertQuery := fmt.Sprintf(`
+WITH snapshots AS (
+%s
+)
 INSERT INTO %s (
   "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId", "CreationTime", "DeletionTime",
   "ResourcePool", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
@@ -379,7 +396,16 @@ INSERT INTO %s (
 )
 SELECT
   "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId", "CreationTime", "DeletionTime",
-  "ResourcePool", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
+  (
+    SELECT s2."ResourcePool"
+    FROM snapshots s2
+    WHERE s2."VmId" = snapshots."VmId"
+      AND s2."Vcenter" = snapshots."Vcenter"
+      AND s2."IsPresent" = 'TRUE'
+    ORDER BY s2."SnapshotTime" DESC
+    LIMIT 1
+  ) AS "ResourcePool",
+  "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
   "RamGB", "IsTemplate", "PoweredOn", "SrmPlaceholder", "VmUuid",
   AVG(CASE WHEN "VcpuCount" IS NOT NULL THEN "VcpuCount" END) AS "AvgVcpuCount",
   AVG(CASE WHEN "RamGB" IS NOT NULL THEN "RamGB" END) AS "AvgRamGB",
@@ -401,14 +427,12 @@ SELECT
     / NULLIF(SUM(CASE WHEN "IsPresent" = 'TRUE' THEN 1 ELSE 0 END), 0) AS "Silver",
   100.0 * SUM(CASE WHEN "IsPresent" = 'TRUE' AND LOWER("ResourcePool") = 'gold' THEN 1 ELSE 0 END)
     / NULLIF(SUM(CASE WHEN "IsPresent" = 'TRUE' THEN 1 ELSE 0 END), 0) AS "Gold"
-FROM (
+FROM snapshots
-%s
-) snapshots
 GROUP BY
   "InventoryId", "Name", "Vcenter", "VmId", "EventKey", "CloudId", "CreationTime", "DeletionTime",
-  "ResourcePool", "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
+  "Datacenter", "Cluster", "Folder", "ProvisionedDisk", "VcpuCount",
   "RamGB", "IsTemplate", "PoweredOn", "SrmPlaceholder", "VmUuid";
-`, monthlyTable, unionQuery)
+`, unionQuery, monthlyTable)
 
 	if _, err := dbConn.ExecContext(ctx, insertQuery); err != nil {
 		c.Logger.Error("failed to aggregate monthly inventory", "error", err, "month", targetMonth.Format("2006-01"))
@@ -870,6 +894,16 @@ func tableHasRows(ctx context.Context, dbConn *sqlx.DB, table string) (bool, err
 	return true, nil
 }
 
+func filterSnapshotsWithRows(ctx context.Context, dbConn *sqlx.DB, snapshots []report.SnapshotRecord) []report.SnapshotRecord {
+	filtered := snapshots[:0]
+	for _, snapshot := range snapshots {
+		if rowsExist, err := tableHasRows(ctx, dbConn, snapshot.TableName); err == nil && rowsExist {
+			filtered = append(filtered, snapshot)
+		}
+	}
+	return filtered
+}
+
 type snapshotTotals struct {
 	VmCount   int64   `db:"vm_count"`
 	VcpuTotal int64   `db:"vcpu_total"`