diff --git a/db/helpers.go b/db/helpers.go
index f4b8b61..70e61b9 100644
--- a/db/helpers.go
+++ b/db/helpers.go
@@ -3418,7 +3418,7 @@ SELECT
   "IsTemplate",
   MAX("PoweredOn") AS "PoweredOn",
   "SrmPlaceholder", "VmUuid",
-  SUM("SamplesPresent") AS "SamplesPresent",
+  CAST(SUM("SamplesPresent") AS BIGINT) AS "SamplesPresent",
   CASE WHEN totals.total_samples > 0
        THEN SUM(CASE WHEN "AvgVcpuCount" IS NOT NULL THEN "AvgVcpuCount" * total_samples_day ELSE 0 END) / totals.total_samples
        ELSE NULL END AS "AvgVcpuCount",
diff --git a/db/helpers_sql_builder_test.go b/db/helpers_sql_builder_test.go
index 2d7ccbb..942f3be 100644
--- a/db/helpers_sql_builder_test.go
+++ b/db/helpers_sql_builder_test.go
@@ -22,3 +22,13 @@ GROUP BY`) {
 		t.Fatalf("unexpected final GROUP BY after agg/totals join; this breaks Postgres SQLSTATE 42803")
 	}
 }
+
+func TestBuildMonthlySummaryInsertCastsSampleSumToBigInt(t *testing.T) {
+	query, err := BuildMonthlySummaryInsert("inventory_monthly_summary_202601", "SELECT 1")
+	if err != nil {
+		t.Fatalf("BuildMonthlySummaryInsert failed: %v", err)
+	}
+	if !strings.Contains(query, `CAST(SUM("SamplesPresent") AS BIGINT) AS "SamplesPresent"`) {
+		t.Fatalf("expected monthly sample sum cast to BIGINT to avoid Postgres numeric assignment issues")
+	}
+}
diff --git a/internal/tasks/canonical_union_test.go b/internal/tasks/canonical_union_test.go
new file mode 100644
index 0000000..0b38ca5
--- /dev/null
+++ b/internal/tasks/canonical_union_test.go
@@ -0,0 +1,39 @@
+package tasks
+
+import (
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestBuildCanonicalHourlySummaryUnionCastsInventoryIDToBigInt(t *testing.T) {
+	start := time.Unix(1700000000, 0).UTC()
+	end := start.Add(24 * time.Hour)
+
+	query := buildCanonicalHourlySummaryUnion(start, end)
+	if !strings.Contains(query, `CAST(NULL AS BIGINT) AS "InventoryId"`) {
+		t.Fatalf("expected InventoryId cast to BIGINT in canonical hourly union query")
+	}
+	if !strings.Contains(query, `CAST(NULL AS TEXT) AS "EventKey"`) {
+		t.Fatalf("expected EventKey cast to TEXT in canonical hourly union query")
+	}
+	if !strings.Contains(query, `CAST(NULL AS TEXT) AS "CloudId"`) {
+		t.Fatalf("expected CloudId cast to TEXT in canonical hourly union query")
+	}
+}
+
+func TestBuildCanonicalDailyRollupSummaryUnionCastsInventoryIDToBigInt(t *testing.T) {
+	start := time.Unix(1700000000, 0).UTC()
+	end := start.AddDate(0, 1, 0)
+
+	query := buildCanonicalDailyRollupSummaryUnion(start, end)
+	if !strings.Contains(query, `CAST(NULL AS BIGINT) AS "InventoryId"`) {
+		t.Fatalf("expected InventoryId cast to BIGINT in canonical daily rollup union query")
+	}
+	if !strings.Contains(query, `CAST(NULL AS TEXT) AS "EventKey"`) {
+		t.Fatalf("expected EventKey cast to TEXT in canonical daily rollup union query")
+	}
+	if !strings.Contains(query, `CAST(NULL AS TEXT) AS "CloudId"`) {
+		t.Fatalf("expected CloudId cast to TEXT in canonical daily rollup union query")
+	}
+}
diff --git a/internal/tasks/dailyAggregate.go b/internal/tasks/dailyAggregate.go
index 8b81e0f..50b04b9 100644
--- a/internal/tasks/dailyAggregate.go
+++ b/internal/tasks/dailyAggregate.go
@@ -313,12 +313,12 @@ func (c *CronTask) aggregateDailySummarySQLCanonical(ctx context.Context, daySta
 func buildCanonicalHourlySummaryUnion(start, end time.Time) string {
 	return fmt.Sprintf(`
 SELECT
-  NULL AS "InventoryId",
+  CAST(NULL AS BIGINT) AS "InventoryId",
   COALESCE("Name",'') AS "Name",
   COALESCE("Vcenter",'') AS "Vcenter",
   COALESCE("VmId",'') AS "VmId",
-  NULL AS "EventKey",
-  NULL AS "CloudId",
+  CAST(NULL AS TEXT) AS "EventKey",
+  CAST(NULL AS TEXT) AS "CloudId",
   COALESCE("CreationTime",0) AS "CreationTime",
   COALESCE("DeletionTime",0) AS "DeletionTime",
   COALESCE("ResourcePool",'') AS "ResourcePool",
diff --git a/internal/tasks/monthlyAggregate.go b/internal/tasks/monthlyAggregate.go
index 13ae511..e022512 100644
--- a/internal/tasks/monthlyAggregate.go
+++ b/internal/tasks/monthlyAggregate.go
@@ -769,12 +769,12 @@ WHERE "Date" >= %d AND "Date" < %d
 func buildCanonicalDailyRollupSummaryUnion(start, end time.Time) string {
 	return fmt.Sprintf(`
 SELECT
-  NULL AS "InventoryId",
+  CAST(NULL AS BIGINT) AS "InventoryId",
   COALESCE("Name",'') AS "Name",
   COALESCE("Vcenter",'') AS "Vcenter",
   COALESCE("VmId",'') AS "VmId",
-  NULL AS "EventKey",
-  NULL AS "CloudId",
+  CAST(NULL AS TEXT) AS "EventKey",
+  CAST(NULL AS TEXT) AS "CloudId",
   COALESCE("CreationTime",0) AS "CreationTime",
   COALESCE("DeletionTime",0) AS "DeletionTime",
   COALESCE("LastResourcePool",'') AS "ResourcePool",