diff --git a/index/upside_down/upside_down.go b/index/upside_down/upside_down.go
index dc20d48b..4731e7ed 100644
--- a/index/upside_down/upside_down.go
+++ b/index/upside_down/upside_down.go
@@ -710,6 +710,7 @@ func (udc *UpsideDownCouch) termFieldVectorsFromTermVectors(in []*TermVector) []
 
 func (udc *UpsideDownCouch) Batch(batch *index.Batch) (err error) {
 	analysisStart := time.Now()
+
 	resultChan := make(chan *index.AnalysisResult, len(batch.IndexOps))
 
 	var numUpdates uint64
@@ -740,12 +741,13 @@ func (udc *UpsideDownCouch) Batch(batch *index.Batch) (err error) {
 		}
 	}()
 
-	udc.writeMutex.Lock()
-	defer udc.writeMutex.Unlock()
-
+	// retrieve back index rows concurrent with analysis
 	var backIndexRows map[string]*BackIndexRow
 	backindexReaderCh := make(chan error)
 
+	udc.writeMutex.Lock()
+	defer udc.writeMutex.Unlock()
+
 	go func() {
 		defer close(backindexReaderCh)
 
@@ -757,7 +759,6 @@ func (udc *UpsideDownCouch) Batch(batch *index.Batch) (err error) {
 			return
 		}
 
-		// first lookup all the back index rows
 		backIndexRows, err = udc.backIndexRowsForBatch(kvreader, batch)
 		if err != nil {
 			_ = kvreader.Close()
@@ -772,7 +773,7 @@ func (udc *UpsideDownCouch) Batch(batch *index.Batch) (err error) {
 		}
 	}()
 
-	// wait for the result
+	// wait for analysis result
 	newRowsMap := make(map[string][]index.IndexRow)
 	var itemsDeQueued uint64
 	for itemsDeQueued < numUpdates {
@@ -782,6 +783,9 @@ func (udc *UpsideDownCouch) Batch(batch *index.Batch) (err error) {
 	}
 	close(resultChan)
 
+	atomic.AddUint64(&udc.stats.analysisTime, uint64(time.Since(analysisStart)))
+
+	// wait for back index rows
 	backindexReaderErr := <-backindexReaderCh
 	if backindexReaderErr != nil {
 		return backindexReaderErr
@@ -793,8 +797,6 @@ func (udc *UpsideDownCouch) Batch(batch *index.Batch) (err error) {
 		return UnsafeBatchUseDetected
 	}
 
-	atomic.AddUint64(&udc.stats.analysisTime, uint64(time.Since(analysisStart)))
-
 	indexStart := time.Now()
 
 	// prepare a list of rows
@@ -845,6 +847,7 @@ func (udc *UpsideDownCouch) Batch(batch *index.Batch) (err error) {
 	}
 
 	err = kvwriter.Close()
+
 	atomic.AddUint64(&udc.stats.indexTime, uint64(time.Since(indexStart)))
 
 	if err == nil {