opt: Invalidate memo if SafeUpdates changes

Do not use cached memo if the SafeUpdates setting does not match.

Release note: None

pkg/sql/opt/memo/memo.go

@@ -137,6 +137,7 @@ type Memo struct {
 	dataConversion    sessiondata.DataConversionConfig
 	reorderJoinsLimit int
 	zigzagJoinEnabled bool
+	safeUpdates       bool
 
 	// curID is the highest currently in-use scalar expression ID.
 	curID opt.ScalarID
@@ -254,7 +255,8 @@ func (m *Memo) IsStale(
 	// changed.
 	if !m.dataConversion.Equals(&evalCtx.SessionData.DataConversion) ||
 		m.reorderJoinsLimit != evalCtx.SessionData.ReorderJoinsLimit ||
-		m.zigzagJoinEnabled != evalCtx.SessionData.ZigzagJoinEnabled {
+		m.zigzagJoinEnabled != evalCtx.SessionData.ZigzagJoinEnabled ||
+		m.safeUpdates != evalCtx.SessionData.SafeUpdates {
 		return true, nil
 	}
 

pkg/sql/opt/memo/memo_test.go

@@ -169,6 +169,24 @@ func TestMemoIsStale(t *testing.T) {
 	evalCtx.SessionData.DataConversion.ExtraFloatDigits = 0
 	notStale()
 
+	// Stale reorder joins limit.
+	evalCtx.SessionData.ReorderJoinsLimit = 4
+	stale()
+	evalCtx.SessionData.ReorderJoinsLimit = 0
+	notStale()
+
+	// Stale zig zag join enable.
+	evalCtx.SessionData.ZigzagJoinEnabled = true
+	stale()
+	evalCtx.SessionData.ZigzagJoinEnabled = false
+	notStale()
+
+	// Stale safe updates.
+	evalCtx.SessionData.SafeUpdates = true
+	stale()
+	evalCtx.SessionData.SafeUpdates = false
+	notStale()
+
 	// Stale data sources and schema. Create new catalog so that data sources are
 	// recreated and can be modified independently.
 	catalog = testcat.New()