diff --git a/model/perf_metric.go b/model/perf_metric.go
index b4a6a9248ed..f081147e703 100644
--- a/model/perf_metric.go
+++ b/model/perf_metric.go
@@ -37,13 +37,17 @@ func UpsertPerfMetric(metric *PerfMetric) error {
 			{Name: "bucket_ts"},
 		},
 		DoUpdates: clause.Assignments(map[string]interface{}{
-			"request_count":    gorm.Expr("request_count + ?", metric.RequestCount),
-			"success_count":    gorm.Expr("success_count + ?", metric.SuccessCount),
-			"total_latency_ms": gorm.Expr("total_latency_ms + ?", metric.TotalLatencyMs),
-			"ttft_sum_ms":      gorm.Expr("ttft_sum_ms + ?", metric.TtftSumMs),
-			"ttft_count":       gorm.Expr("ttft_count + ?", metric.TtftCount),
-			"output_tokens":    gorm.Expr("output_tokens + ?", metric.OutputTokens),
-			"generation_ms":    gorm.Expr("generation_ms + ?", metric.GenerationMs),
+			// Qualify the right-hand column with the table name. PostgreSQL (>=14.4)
+			// treats an unqualified column in ON CONFLICT DO UPDATE as ambiguous
+			// between the existing row and the excluded row. Table-qualified names
+			// are accepted by SQLite/MySQL/PostgreSQL alike.
+			"request_count":    gorm.Expr("perf_metrics.request_count + ?", metric.RequestCount),
+			"success_count":    gorm.Expr("perf_metrics.success_count + ?", metric.SuccessCount),
+			"total_latency_ms": gorm.Expr("perf_metrics.total_latency_ms + ?", metric.TotalLatencyMs),
+			"ttft_sum_ms":      gorm.Expr("perf_metrics.ttft_sum_ms + ?", metric.TtftSumMs),
+			"ttft_count":       gorm.Expr("perf_metrics.ttft_count + ?", metric.TtftCount),
+			"output_tokens":    gorm.Expr("perf_metrics.output_tokens + ?", metric.OutputTokens),
+			"generation_ms":    gorm.Expr("perf_metrics.generation_ms + ?", metric.GenerationMs),
 		}),
 	}).Create(metric).Error
 }
diff --git a/pkg/perf_metrics/flush.go b/pkg/perf_metrics/flush.go
index dddc2472585..32af174acc5 100644
--- a/pkg/perf_metrics/flush.go
+++ b/pkg/perf_metrics/flush.go
@@ -51,8 +51,15 @@ func flushCompletedBuckets() {
 			GenerationMs:   drained.generationMs,
 		})
 		if err != nil {
-			bucket.addCounters(drained)
 			common.SysError(fmt.Sprintf("failed to flush perf metric bucket model=%s group=%s bucket=%d: %s", k.model, k.group, k.bucketTs, err.Error()))
+			// Give up on buckets that have been failing past the 24h horizon instead
+			// of retrying (and holding memory) forever; otherwise a persistently
+			// failing flush leaks memory and spams logs indefinitely.
+			if k.bucketTs < bucketStart(time.Now().Add(-24*time.Hour).Unix()) {
+				hotBuckets.Delete(key)
+				return true
+			}
+			bucket.addCounters(drained)
 			return true
 		}