diff --git a/HLD/Nearby-Theater-Schedule.md b/doc/Nearby-Theater-Schedule.md
similarity index 100%
rename from HLD/Nearby-Theater-Schedule.md
rename to doc/Nearby-Theater-Schedule.md
diff --git a/doc/dbSetup.md b/doc/dbSetup.md
new file mode 100644
index 0000000..e52f893
--- /dev/null
+++ b/doc/dbSetup.md
@@ -0,0 +1,19 @@
+# Create index
+To speed up db query, we need to create index
+1. yahooMovies : yahooId: -1
+2. pttArticles : url: -1
+
+### Sample command
+```
+db.runCommand({
+  "createIndexes": "pttArticles",
+  "indexes": [
+    {
+      "key": {
+        "url": -1
+      },
+      "name": "url"
+    }
+  ]
+})
+```
\ No newline at end of file
diff --git a/src/task/imdbTask.ts b/src/task/imdbTask.ts
index 0ce7055..22222d3 100644
--- a/src/task/imdbTask.ts
+++ b/src/task/imdbTask.ts
@@ -4,13 +4,15 @@ import { getIMDBMovieInfo } from '../crawler/imdbCrawler';
 import Movie from "../models/movie";
 
 export async function updateImdbInfo() {
-    const movieInfos = await getNewImdbInfos();
+    let movieInfos = await getNewImdbInfos();
+    removeEmptyInfos(movieInfos);
     logResult(movieInfos);
     return updateYahooMovies(movieInfos);
 }
 
+const imdbLastCrawlTimeFormat = 'YYYY-MM-DDTHH';
 async function getNewImdbInfos() {
-    const imdbLastCrawlTime = moment().format('YYYY-MM-DD');
+    const imdbLastCrawlTime = moment().format(imdbLastCrawlTimeFormat);
     const yahooMovies: Movie[] = await db.getCollection("yahooMovies");
     const promises = yahooMovies.filter(filterNeedCrawlMovie).map(async ({ englishTitle, yahooId }) => {
         const imdbInfo = await getIMDBMovieInfo(englishTitle);
@@ -23,14 +25,21 @@ async function getNewImdbInfos() {
     return Promise.all(promises);
 }
 
-function filterNeedCrawlMovie({ englishTitle, imdbRating, releaseDate, imdbLastCrawlTime }: Movie) {
+function filterNeedCrawlMovie({ englishTitle, releaseDate, imdbLastCrawlTime }: Movie) {
     let now = moment();
     let isRecentMovie = now.diff(moment(releaseDate), 'months') <= 6;
-    let hasCrawlToday = imdbLastCrawlTime && (now.diff(moment(imdbLastCrawlTime), 'days') === 0);
-    let shouldCrawl = !hasCrawlToday && englishTitle && (isRecentMovie || (!isRecentMovie && !imdbLastCrawlTime));
+    let hasCrawlNearly = imdbLastCrawlTime && (now.diff(moment(imdbLastCrawlTime, imdbLastCrawlTimeFormat), 'hours') <= 12);
+    let shouldCrawl = !hasCrawlNearly && englishTitle && (isRecentMovie || (!isRecentMovie && !imdbLastCrawlTime));
     return shouldCrawl;
 }
 
+function removeEmptyInfos(movieInfos: Movie[]){
+    movieInfos.forEach(info=>{
+        !info.imdbID && delete info.imdbID;
+        !info.imdbRating && delete info.imdbRating;
+    })
+}
+
 function logResult(movieInfos: Movie[]) {
     const foundMovies = movieInfos.filter(movie => movie.imdbID);
     const notfoundMovieIds = movieInfos.filter(movie => !movie.imdbID).map(movie => movie.yahooId);
diff --git a/src/test/imdbTask.test.ts b/src/test/imdbTask.test.ts
index 7f52764..a6c2787 100644
--- a/src/test/imdbTask.test.ts
+++ b/src/test/imdbTask.test.ts
@@ -11,29 +11,40 @@ const should = chai.should();
 chai.use(sinonChai);
 
 describe('imdbTask', () => {
-  let sandbox, stubUpdateDocument, stubGetCollection: sinon.SinonStub;
-  before(() => {
+  let sandbox: sinon.SinonSandbox, stubUpdateDocument: sinon.SinonStub, stubGetCollection: sinon.SinonStub;
+  beforeEach(() => {
     sandbox = sinon.sandbox.create();
     stubUpdateDocument = sandbox.stub(db, 'updateDocument');
     stubGetCollection = sandbox.stub(db, 'getCollection');
   });
 
-  after(() => {
+  afterEach(() => {
     sandbox.restore();
   });
 
   describe('updateImdbInfo', () => {
-    it("should get yahooMovies then update nearly movies' imdb info", async function () {
-      const yahooMovies: Movie[] = [{
-        yahooId: 6777,
-        englishTitle: 'Dangal',
-        releaseDate: moment().format(),
-        imdbLastCrawlTime: moment().subtract(2, 'days').format()
-      }]
-      stubGetCollection.returns(yahooMovies);
-      const stubGetIMDBMovieInfo = sandbox.stub(imdbCrawler, 'getIMDBMovieInfo').returns([1]);
+    const yahooMovie: Movie = {
+      yahooId: 6777,
+      englishTitle: 'Dangal',
+      releaseDate: moment().format(),
+      imdbLastCrawlTime: moment().subtract(2, 'days').format()
+    };
+
+
+    it("One yahooMovie should called GetIMDBMovieInfo Once", async function () {
+      stubGetCollection.returns([yahooMovie]);
+      const stubGetIMDBMovieInfo = sandbox.stub(imdbCrawler, 'getIMDBMovieInfo').returns({ imdbID: "", imdbRating: "" });
+      await updateImdbInfo();
+      sandbox.assert.calledOnce(stubGetIMDBMovieInfo);
+    });
+
+    it("should update db without info when it's empty", async function () {
+      stubGetCollection.returns([yahooMovie]);
+      const stubGetIMDBMovieInfo = sandbox.stub(imdbCrawler, 'getIMDBMovieInfo').returns({ imdbID: "", imdbRating: "" });
       await updateImdbInfo();
-      sandbox.assert.calledOnce(stubUpdateDocument);
+      sandbox.assert.calledWith(stubUpdateDocument,
+        { yahooId: yahooMovie.yahooId },
+        { yahooId: yahooMovie.yahooId, imdbLastCrawlTime: moment().format('YYYY-MM-DDTHH') });
     });
   });
 });
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