From 19807ff3a72ed6a2d9d55079af44eae466b16dac Mon Sep 17 00:00:00 2001
From: Matt Jaffee <matthew.jaffee@gmail.com>
Date: Sat, 9 Mar 2019 21:51:08 -0600
Subject: [PATCH] use num containers to decide which direction to union

avoids doing a potentially expensive f.storage.Count()
---
 fragment.go | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/fragment.go b/fragment.go
index c09461470..0c4ff5dd6 100644
--- a/fragment.go
+++ b/fragment.go
@@ -1750,15 +1750,11 @@ func (f *fragment) importRoaring(data []byte, clear bool) error {
 
 	if clear {
 		bm = f.storage.Difference(bm)
+	} else if f.storage.Containers.Size() >= bm.Containers.Size() {
+		f.storage.UnionInPlace(bm)
+		bm = f.storage
 	} else {
-		if cnt := f.storage.Count(); cnt > 0 {
-			if incomingCnt > int(cnt) {
-				bm.UnionInPlace(f.storage)
-			} else {
-				f.storage.UnionInPlace(bm)
-				bm = f.storage
-			}
-		}
+		bm.UnionInPlace(f.storage)
 	}
 
 	for _, rowID := range rowSet {