From 5927224e15dcecf1b8f48490568492ff4e5c3b56 Mon Sep 17 00:00:00 2001
From: Steve Yen <steve.yen@gmail.com>
Date: Mon, 9 Jan 2017 22:48:55 -0800
Subject: [PATCH] optimize mergeOldAndNew for case of first time a doc is seen

---
 index/upsidedown/upsidedown.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/index/upsidedown/upsidedown.go b/index/upsidedown/upsidedown.go
index 80bbfeaf..1bf9c733 100644
--- a/index/upsidedown/upsidedown.go
+++ b/index/upsidedown/upsidedown.go
@@ -499,6 +499,15 @@ func (udc *UpsideDownCouch) Update(doc *document.Document) (err error) {
 
 func (udc *UpsideDownCouch) mergeOldAndNew(backIndexRow *BackIndexRow, rows []index.IndexRow) (addRows []UpsideDownCouchRow, updateRows []UpsideDownCouchRow, deleteRows []UpsideDownCouchRow) {
 	addRows = make([]UpsideDownCouchRow, 0, len(rows))
+
+	if backIndexRow == nil {
+		addRows = addRows[0:len(rows)]
+		for i, row := range rows {
+			addRows[i] = row
+		}
+		return addRows, nil, nil
+	}
+
 	updateRows = make([]UpsideDownCouchRow, 0, len(rows))
 	deleteRows = make([]UpsideDownCouchRow, 0, len(rows))