Row count is incorrect when using aggregator connections. Closes #402

Author: kaidaguerre

.idea/modules.xml

@@ -195,26 +195,24 @@ func (h *Hub) AddScanMetadata(iter Iterator) {
 		return
 	}
 
-	// get list of scan metadata from iterator (may be more than 1 for group_iterator)
-	scanMetadata := iter.GetScanMetadata()
-	for _, m := range scanMetadata {
-		// set ID
-		m.Id = id
-		id++
-		log.Printf("[TRACE] got metadata table: %s cache hit: %v, rows fetched %d, hydrate calls: %d",
-			m.Table, m.CacheHit, m.RowsFetched, m.HydrateCalls)
-		// read the scan metadata from the iterator and add to our stack
-		h.scanMetadata = append(h.scanMetadata, m)
-
-		// hydrate metric labels
-		labels := []attribute.KeyValue{
-			attribute.String("table", m.Table),
-			attribute.String("connection", connectionName),
-			attribute.String("plugin", connectionPlugin.PluginName),
-		}
-		log.Printf("[TRACE] update hydrate calls counter with %d", m.HydrateCalls)
-		h.hydrateCallsCounter.Add(ctx, m.HydrateCalls, metric.WithAttributes(labels...))
+	// get scan metadata from iterator
+	m := iter.GetScanMetadata()
+
+	// set ID
+	m.Id = id
+	log.Printf("[TRACE] got metadata table: %s cache hit: %v, rows fetched %d, hydrate calls: %d",
+		m.Table, m.CacheHit, m.RowsFetched, m.HydrateCalls)
+	// read the scan metadata from the iterator and add to our stack
+	h.scanMetadata = append(h.scanMetadata, m)
+
+	// hydrate metric labels
+	labels := []attribute.KeyValue{
+		attribute.String("table", m.Table),
+		attribute.String("connection", connectionName),
+		attribute.String("plugin", connectionPlugin.PluginName),
 	}
+	log.Printf("[TRACE] update hydrate calls counter with %d", m.HydrateCalls)
+	h.hydrateCallsCounter.Add(ctx, m.HydrateCalls, metric.WithAttributes(labels...))
 
 	// now trim scan metadata - max 1000 items
 	const maxMetadataItems = 1000

.idea/steampipe-postgres-fdw.iml

@@ -65,8 +65,8 @@ func (i *inMemoryIterator) CanIterate() bool {
 	}
 }
 
-func (i *inMemoryIterator) GetScanMetadata() []ScanMetadata {
-	return nil
+func (i *inMemoryIterator) GetScanMetadata() ScanMetadata {
+	return ScanMetadata{}
 }
 func (i *inMemoryIterator) GetTraceContext() *telemetry.TraceCtx {
 	return &telemetry.TraceCtx{Ctx: context.Background()}

hub/hub.go

@@ -14,6 +14,6 @@ type Iterator interface {
 	Status() queryStatus
 	Error() error
 	CanIterate() bool
-	GetScanMetadata() []ScanMetadata
+	GetScanMetadata() ScanMetadata
 	GetTraceContext() *telemetry.TraceCtx
 }

hub/in_memory_iterator.go

@@ -173,23 +173,24 @@ func (i *scanIterator) CanIterate() bool {
 
 }
 
-func (i *scanIterator) GetScanMetadata() []ScanMetadata {
-	res := make([]ScanMetadata, len(i.scanMetadata))
-	idx := 0
+// GetScanMetadata returns the scan metadata for this iterator
+// note: if this is an aggregator query, we will have a scan metadata for each connection
+// we need to combine them into a single scan metadata object
+func (i *scanIterator) GetScanMetadata() ScanMetadata {
+	res := ScanMetadata{
+		Table:     i.table,
+		Columns:   i.queryContext.Columns,
+		Quals:     i.queryContext.Quals,
+		StartTime: i.startTime,
+		Duration:  time.Since(i.startTime),
+	}
 	for _, m := range i.scanMetadata {
-		res[idx] = ScanMetadata{
-			Table:        i.table,
-			CacheHit:     m.CacheHit,
-			RowsFetched:  m.RowsFetched,
-			HydrateCalls: m.HydrateCalls,
-			Columns:      i.queryContext.Columns,
-			Quals:        i.queryContext.Quals,
-			StartTime:    i.startTime,
-			Duration:     time.Since(i.startTime),
-		}
-		idx++
+		res.CacheHit = res.CacheHit || m.CacheHit
+		res.RowsFetched += m.RowsFetched
+		res.HydrateCalls += m.HydrateCalls
 	}
 	return res
+
 }
 
 func (i *scanIterator) GetTraceContext() *telemetry.TraceCtx {