From e9631668cc60aa1aa12325668c0d49d8f3109d3d Mon Sep 17 00:00:00 2001
From: Jian Zhang <zjsariel@gmail.com>
Date: Mon, 16 Apr 2018 19:11:58 +0800
Subject: [PATCH 1/2] variable: set default hash join concurrency in
 NewSessionVars

---
 sessionctx/variable/session.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sessionctx/variable/session.go b/sessionctx/variable/session.go
index 74ea322e290f9..b6960cb67b2af 100644
--- a/sessionctx/variable/session.go
+++ b/sessionctx/variable/session.go
@@ -347,6 +347,7 @@ func NewSessionVars() *SessionVars {
 		IndexLookupConcurrency:     DefIndexLookupConcurrency,
 		IndexSerialScanConcurrency: DefIndexSerialScanConcurrency,
 		IndexLookupJoinConcurrency: DefIndexLookupJoinConcurrency,
+		HashJoinConcurrency:        DefTiDBHashJoinConcurrency,
 		DistSQLScanConcurrency:     DefDistSQLScanConcurrency,
 		MaxChunkSize:               DefMaxChunkSize,
 		DMLBatchSize:               DefDMLBatchSize,

From ed469e46f3349e50c878246dab7f8a09d5389133 Mon Sep 17 00:00:00 2001
From: Jian Zhang <zjsariel@gmail.com>
Date: Mon, 16 Apr 2018 19:22:45 +0800
Subject: [PATCH 2/2] add UT for NewSessionVars()

---
 sessionctx/variable/varsutil_test.go | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/sessionctx/variable/varsutil_test.go b/sessionctx/variable/varsutil_test.go
index 74eb2d14bdbc8..6c9262a666490 100644
--- a/sessionctx/variable/varsutil_test.go
+++ b/sessionctx/variable/varsutil_test.go
@@ -52,6 +52,30 @@ func (s *testVarsutilSuite) TestTiDBOptOn(c *C) {
 	}
 }
 
+func (s *testVarsutilSuite) TestNewSessionVars(c *C) {
+	defer testleak.AfterTest(c)()
+	vars := NewSessionVars()
+
+	c.Assert(vars.BuildStatsConcurrencyVar, Equals, DefBuildStatsConcurrency)
+	c.Assert(vars.IndexJoinBatchSize, Equals, DefIndexJoinBatchSize)
+	c.Assert(vars.IndexLookupSize, Equals, DefIndexLookupSize)
+	c.Assert(vars.IndexLookupConcurrency, Equals, DefIndexLookupConcurrency)
+	c.Assert(vars.IndexSerialScanConcurrency, Equals, DefIndexSerialScanConcurrency)
+	c.Assert(vars.IndexLookupJoinConcurrency, Equals, DefIndexLookupJoinConcurrency)
+	c.Assert(vars.HashJoinConcurrency, Equals, DefTiDBHashJoinConcurrency)
+	c.Assert(vars.DistSQLScanConcurrency, Equals, DefDistSQLScanConcurrency)
+	c.Assert(vars.MaxChunkSize, Equals, DefMaxChunkSize)
+	c.Assert(vars.DMLBatchSize, Equals, DefDMLBatchSize)
+	c.Assert(vars.MemQuotaQuery, Equals, int64(DefTiDBMemQuotaQuery))
+	c.Assert(vars.MemQuotaHashJoin, Equals, int64(DefTiDBMemQuotaHashJoin))
+	c.Assert(vars.MemQuotaMergeJoin, Equals, int64(DefTiDBMemQuotaMergeJoin))
+	c.Assert(vars.MemQuotaSort, Equals, int64(DefTiDBMemQuotaSort))
+	c.Assert(vars.MemQuotaTopn, Equals, int64(DefTiDBMemQuotaTopn))
+	c.Assert(vars.MemQuotaIndexLookupReader, Equals, int64(DefTiDBMemQuotaIndexLookupReader))
+	c.Assert(vars.MemQuotaIndexLookupJoin, Equals, int64(DefTiDBMemQuotaIndexLookupJoin))
+	c.Assert(vars.MemQuotaNestedLoopApply, Equals, int64(DefTiDBMemQuotaNestedLoopApply))
+}
+
 func (s *testVarsutilSuite) TestVarsutil(c *C) {
 	defer testleak.AfterTest(c)()
 	v := NewSessionVars()