diff --git a/packages/analytics/src/combine.js b/packages/analytics/src/combine.js
index 508f4a6c..619696e0 100644
--- a/packages/analytics/src/combine.js
+++ b/packages/analytics/src/combine.js
@@ -2,25 +2,31 @@ import get from 'lodash.get';
 import set from 'lodash.set';
 import debug from 'debug';
 import assert from 'assert';
-import crypto from 'crypto';
-import { createStore, createPersistentStore } from '@ezs/store';
+import hasher from 'node-object-hash';
+import core from './core';
+
+const hashCoerce = hasher({ sort: false, coerce: true });
+
+const database = {};
 
 async function saveIn(data, feed) {
     if (this.isLast()) {
         return feed.close();
     }
-    const store = this.getEnv();
-    const key = get(data, 'id');
-    const isKey = Boolean(key);
+    const databaseID = this.getEnv();
+    const { id, value } = data;
+    const isKey = Boolean(id);
     if (isKey) {
-        await store.put(key, data);
+        if (!database[databaseID]) {
+            database[databaseID] = {};
+        }
+        if (!database[databaseID][id]) {
+            database[databaseID][id] = value;
+        }
     }
-    return feed.send(key);
+    return feed.send(id);
 }
 
-function sha1(input, salt) {
-    return crypto.createHash('sha1').update(JSON.stringify(input) + String(salt)).digest('hex');
-}
 
 /**
  * Takes an `Object` and substitute a field with the corresponding value found in a external pipeline
@@ -59,23 +65,19 @@ function sha1(input, salt) {
  * @name combine
  * @param {String} [path] the path to substitute
  * @param {String} [default] value if no substitution (otherwise value stay unchanged)
- * @param {String} [primer=auto] Data to send to the external pipeline
+ * @param {String} [primer=n/a] Data to send to the external pipeline
  * @param {String} [file] the external pipeline is described in a file
  * @param {String} [script] the external pipeline is described in a string of characters
  * @param {String} [commands] the external pipeline is described in a object
  * @param {String} [command] the external pipeline is described in a URL-like command
- * @param {String} [cacheName] Enable cache, with dedicated name
  * @returns {Object}
  */
 export default function combine(data, feed) {
     const { ezs } = this;
-    const cacheName = this.getParam('cacheName');
-    const persistent = Boolean(cacheName);
     let whenReady = Promise.resolve(true);
     if (this.isFirst()) {
         debug('ezs')('[combine] with sub pipeline.');
-        const location = this.getParam('location');
-        const primer = this.getParam('primer');
+        const primer = this.getParam('primer', 'n/a');
         const input = ezs.createStream(ezs.objectMode());
         const commands = ezs.createCommands({
             file: this.getParam('file'),
@@ -85,33 +87,22 @@ export default function combine(data, feed) {
             prepend: this.getParam('prepend'),
             append: this.getParam('append'),
         });
-        if (persistent) {
-            this.store = createPersistentStore(ezs, `combine${cacheName}`, location);
-        } else {
-            this.store = createStore(ezs, 'combine', location);
-        }
-        if (persistent && !this.store.isCreated()) {
-            whenReady = Promise.resolve(true);
-        } else {
-            const statements = ezs.compileCommands(commands, this.getEnv());
-            const output = ezs.createPipeline(input, statements)
-                .pipe(ezs(saveIn, null, this.store))
-                .pipe(ezs.catch())
-                .on('data', (d) => assert(d)) // WARNING: The data must be consumed, otherwise the "end" event has not been triggered
-                .on('error', (e) => feed.stop(e));
-            whenReady = new Promise((resolve) => output.on('end', resolve));
-            input.write(primer || this.store.id());
-            input.end();
-        }
+        this.databaseID = hashCoerce.hash({ primer, commands });
+        const statements = ezs.compileCommands(commands, this.getEnv());
+        const output = ezs.createPipeline(input, statements)
+            .pipe(ezs(saveIn, null, this.databaseID))
+            .pipe(ezs.catch())
+            .on('data', (d) => assert(d)) // WARNING: The data must be consumed, otherwise the "end" event has not been triggered
+            .on('error', (e) => feed.stop(e));
+        whenReady = new Promise((resolve) => output.on('end', resolve));
+        input.write(primer);
+        input.end();
     }
     if (this.isLast()) {
-        if (!persistent) {
-            this.store.close();
-        }
         return feed.close();
     }
     return whenReady
-        .then(async () => {
+        .then(() => {
             const defval = this.getParam('default', null);
             const path = this.getParam('path');
             const pathVal = get(data, path);
@@ -119,7 +110,12 @@ export default function combine(data, feed) {
             if (keys.length === 0) {
                 return feed.send(data);
             }
-            const values = await Promise.all(keys.map((key) => this.store.get(key)));
+            const values = keys.map((key) => {
+                if (!database[this.databaseID][key]) {
+                    return null;
+                }
+                return core(key, database[this.databaseID][key]);
+            });
             if (values.length && Array.isArray(pathVal)) {
                 set(data, path, values);
             } else if (values.length && !Array.isArray(pathVal)) {
@@ -141,9 +137,6 @@ export default function combine(data, feed) {
             return feed.send(data);
         })
         .catch((e) => {
-            if (this.store) {
-                this.store.close();
-            }
             feed.stop(e);
         });
 }
diff --git a/packages/analytics/test/combine.js b/packages/analytics/test/combine.js
index 8c152433..6e6e9a47 100644
--- a/packages/analytics/test/combine.js
+++ b/packages/analytics/test/combine.js
@@ -38,7 +38,9 @@ describe('combine', () => {
                 output.push(chunk);
             })
             .on('end', () => {
+
                 assert.equal(output.length, 6);
+                console.log(output, output[0], output[0]);
                 assert.equal(output[0].b.value, 'aa');
                 assert.equal(output[1].b.value, 'bb');
                 assert.equal(output[2].b.value, 'cc');
@@ -340,7 +342,7 @@ describe('no combine', () => {
                 done(new Error('Error is the right behavior'));
             });
     });
-    test('with wrong location', (done) => {
+    test.skip('with wrong location', (done) => {
         ezs.use(statements);
         const input = [
             { a: 1, b: 'a' },
@@ -383,7 +385,7 @@ const env = {
 };
 const cacheName = Date.now();
 
-test('combine with cache with script #1', (done) => {
+test.skip('combine with cache with script #1', (done) => {
     ezs.use(statements);
     const input = [
         { a: 1, b: 'a' },
@@ -431,7 +433,7 @@ test('combine with cache with script #1', (done) => {
         });
 });
 
-test('combine with cache with script #2', (done) => {
+test.skip('combine with cache with script #2', (done) => {
     ezs.use(statements);
     const input = [
         { a: 1, b: 'a' },