From 253c47c88fbc1a65acaf05dd4b33c4fbe918b20c Mon Sep 17 00:00:00 2001
From: Inada Naoki <songofacandy@gmail.com>
Date: Wed, 3 Apr 2019 21:33:13 +0900
Subject: [PATCH 1/2] add benchmark for sql.RawBytes

---
 benchmark_test.go | 49 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/benchmark_test.go b/benchmark_test.go
index 5828d40f9..869784c7a 100644
--- a/benchmark_test.go
+++ b/benchmark_test.go
@@ -317,3 +317,52 @@ func BenchmarkExecContext(b *testing.B) {
 		})
 	}
 }
+
+// BenchmarkQueryRawBytes benchmarks fetching 100 blobs using sql.RawBytes.
+// "size=" means size of each blobs.
+func BenchmarkQueryRawBytes(b *testing.B) {
+	var sizes []int = []int{100, 1000, 2000, 4000, 8000, 12000, 16000, 32000, 64000, 256000}
+	db := initDB(b,
+		"DROP TABLE IF EXISTS bench_rawbytes",
+		"CREATE TABLE bench_rawbytes (id INT PRIMARY KEY, val LONGBLOB)",
+	)
+	defer db.Close()
+
+	blob := make([]byte, sizes[len(sizes)-1])
+	for i := range blob {
+		blob[i] = 42
+	}
+	for i := 0; i < 100; i++ {
+		_, err := db.Exec("INSERT INTO bench_rawbytes VALUES (?, ?)", i, blob)
+		if err != nil {
+			b.Fatal(err)
+		}
+	}
+	for _, s := range sizes {
+		b.Run(fmt.Sprintf("size=%v", s), func(b *testing.B) {
+			b.ReportAllocs()
+			for j := 0; j < b.N; j++ {
+				rows, err := db.Query("SELECT LEFT(val, ?) as v FROM bench_rawbytes", s)
+				if err != nil {
+					b.Fatal(err)
+				}
+				nrows := 0
+				for rows.Next() {
+					var buf sql.RawBytes
+					err := rows.Scan(&buf)
+					if err != nil {
+						b.Fatal(err)
+					}
+					if len(buf) != s {
+						b.Fatalf("size mismatch: expected %v, got %v", s, len(buf))
+					}
+					nrows++
+				}
+				rows.Close()
+				if nrows != 100 {
+					b.Fatalf("numbers of rows mismatch: expected %v, got %v", 100, nrows)
+				}
+			}
+		})
+	}
+}

From 5d1faf2480f507d2e4ba48f01c7733f2284f0651 Mon Sep 17 00:00:00 2001
From: Inada Naoki <songofacandy@gmail.com>
Date: Thu, 4 Apr 2019 11:49:51 +0900
Subject: [PATCH 2/2] don't reuse connection over subbenchs

---
 benchmark_test.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/benchmark_test.go b/benchmark_test.go
index 869784c7a..3e25a3bf2 100644
--- a/benchmark_test.go
+++ b/benchmark_test.go
@@ -338,9 +338,14 @@ func BenchmarkQueryRawBytes(b *testing.B) {
 			b.Fatal(err)
 		}
 	}
+
 	for _, s := range sizes {
 		b.Run(fmt.Sprintf("size=%v", s), func(b *testing.B) {
+			db.SetMaxIdleConns(0)
+			db.SetMaxIdleConns(1)
 			b.ReportAllocs()
+			b.ResetTimer()
+
 			for j := 0; j < b.N; j++ {
 				rows, err := db.Query("SELECT LEFT(val, ?) as v FROM bench_rawbytes", s)
 				if err != nil {