yardz commented on a change in pull request #13497:
URL: https://github.com/apache/superset/pull/13497#discussion_r591537780



##########
File path: 
superset-frontend/src/components/DatabaseSelector/changeDataBase/useChangeDataBase.ts
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@@ -0,0 +1,64 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import React, { useEffect, useRef } from 'react';
+import { FetchSchemas } from '../fetchSchemas';
+import { OnSelectChange } from '../onSelectChange';
+import { factoryChangeDataBase } from './factoryChangeDataBase';
+
+export const useChangeDataBase = ({
+  setSchemaOptions,
+  fetchSchemas,
+  onSchemaChange,
+  onDbChange,
+  onSelectChange,
+}: {
+  setSchemaOptions: (options: any[]) => void;
+  fetchSchemas: React.MutableRefObject<FetchSchemas>;
+  onSchemaChange?: (arg0?: any) => {};
+  onDbChange?: (db: any) => void;
+  onSelectChange: React.MutableRefObject<OnSelectChange>;
+}) => {
+  const changeDataBase = useRef(
+    factoryChangeDataBase({
+      setSchemaOptions,
+      fetchSchemas,
+      onSchemaChange,
+      onDbChange,
+      onSelectChange,
+    }),
+  );
+  useEffect(() => {

Review comment:
       `useCallback` does not tackle the problem the way I wanted it. It will 
generate a new function every time a parameter changes and will cause a new 
render.
   As there are several functions that depend on each other, several rendes 
will be caused by this. When the `current` value is updated, a render is not 
trigged (which is why I don't return the `current` either).
   
   The idea there is to behave like a class property. I want to change the 
value of these functions without triggering a new render. And of course, from 
the moment that this value is changed, everyone who uses this function (and has 
received these props in the past) will access the new value without a new 
rendering.
   
   The combination of `useEffect` + `useRef` allows me to do this. Using 
`useCallback` or `useMemo` does not do this.




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