bindinfo: fix bindinfo bugs when update cache (#13875)

bindinfo/bind_test.go

@@ -99,8 +99,8 @@ func (s *testSuite) TearDownTest(c *C) {
 }
 
 func (s *testSuite) cleanBindingEnv(tk *testkit.TestKit) {
-	tk.MustExec("drop table if exists mysql.bind_info")
-	tk.MustExec(session.CreateBindInfoTable)
+	tk.MustExec("truncate table mysql.bind_info")
+	s.domain.BindHandle().Clear()
 }
 
 func (s *testSuite) TestBindParse(c *C) {
@@ -465,3 +465,21 @@ func (s *testSuite) TestErrorBind(c *C) {
 	c.Check(err, IsNil)
 	c.Check(chk.NumRows(), Equals, 0)
 }
+
+func (s *testSuite) TestBindingCache(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	s.cleanBindingEnv(tk)
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int, b int, index idx(a))")
+	tk.MustExec("create global binding for select * from t using select * from t use index(idx)")
+	tk.MustExec("create database tmp")
+	tk.MustExec("use tmp")
+	tk.MustExec("create table t(a int, b int, index idx(a))")
+	tk.MustExec("create global binding for select * from t using select * from t use index(idx)")
+
+	c.Assert(s.domain.BindHandle().Update(false), IsNil)
+	c.Assert(s.domain.BindHandle().Update(false), IsNil)
+	res := tk.MustQuery("show global bindings")
+	c.Assert(len(res.Rows()), Equals, 2)
+}

bindinfo/handle.go

@@ -95,7 +95,7 @@ func NewBindHandle(ctx sessionctx.Context) *BindHandle {
 func (h *BindHandle) Update(fullLoad bool) (err error) {
 	sql := "select original_sql, bind_sql, default_db, status, create_time, update_time, charset, collation from mysql.bind_info"
 	if !fullLoad {
-		sql += " where update_time >= \"" + h.lastUpdateTime.String() + "\""
+		sql += " where update_time > \"" + h.lastUpdateTime.String() + "\""
 	}
 
 	// No need to acquire the session context lock for ExecRestrictedSQL, it
@@ -358,6 +358,7 @@ func (c cache) removeDeletedBindMeta(hash string, meta *BindMeta, scope string)
 			}
 		}
 	}
+	c[hash] = metas
 }
 
 // removeStaleBindMetas removes all the stale BindMeta in the cache.
@@ -377,12 +378,15 @@ func (c cache) removeStaleBindMetas(hash string, meta *BindMeta, scope string) {
 			}
 		}
 	}
+	c[hash] = metas
 }
 
 func (c cache) copy() cache {
 	newCache := make(cache, len(c))
 	for k, v := range c {
-		newCache[k] = v
+		bindMetas := make([]*BindMeta, len(v))
+		copy(bindMetas, v)
+		newCache[k] = bindMetas
 	}
 	return newCache
 }
@@ -445,3 +449,10 @@ func (h *BindHandle) logicalDeleteBindInfoSQL(normdOrigSQL, db string, updateTs
 		expression.Quote(normdOrigSQL),
 		expression.Quote(db))
 }
+
+// Clear resets the bind handle. It is used for test.
+func (h *BindHandle) Clear() {
+	h.bindInfo.Store(make(cache))
+	h.invalidBindRecordMap.Store(make(map[string]*invalidBindRecordMap))
+	h.lastUpdateTime = types.ZeroTimestamp
+}