diff --git a/README.md b/README.md
index 5230dc0..6a1ea90 100644
--- a/README.md
+++ b/README.md
@@ -10,18 +10,29 @@ Setup file(s) for OPAL data server with one Elasticsearch and one Apache Fuseki
 - Edit the configuration file  `.env`.  
   Settings:
     - `FUSEKI_ADMIN_PASSWORD`  
-      If not set, a random password will be created.
+      Fuseki admin password for the frontend. If not set, a random password will be created.
     - `FUSEKI_JVM_ARGS`  
-    Java configuration, e.g. the maximum heap size (Xmx), default is -Xmx16g.
+      Java configuration for Fuseki, e.g. the maximum heap size (Xmx).  
+      Default value: `-Xmx16g`
+    - `ELASTICSEARCH_JAVA_OPTS`  
+      Java memory configuration for Elasticsearch.  
+      Default value: `-Xms512m -Xmx16g`
 - Run `docker-compose up -d`
 
 ## Access
 
-- Fuseki  
+- **Fuseki**  
   URL: `http://localhost:3030/`  
   Username: `admin`  
   Password: As set in .env file or randomly created.
+- **Elasticsearch**  
+  An example to add a dataset:  
+  `curl -H "Content-Type: application/json" -XPOST "http://localhost:9200/opal/dataset/test123" -d "{ \"title\" : \"Hello World\"}"`  
+  An example to get a dataset:  
+  `curl -XGET http://localhost:9200/opal/dataset/test123`  
+  An example to count datasets:  
+  `curl -XGET http://localhost:9200/catalog/dataset/_count`
 
 ## Notes 
 
-* Some documentation is in the GitHub wiki: https://github.com/projekt-opal/opaldata/wiki
\ No newline at end of file
+* Some documentation is in the GitHub wiki: https://github.com/projekt-opal/opaldata/wiki
diff --git a/elasticsearch/run.sh b/elasticsearch/run.sh
index 3d459d3..32ed20d 100644
--- a/elasticsearch/run.sh
+++ b/elasticsearch/run.sh
@@ -1,2 +1,2 @@
-curl -XPUT 'http://elastic:changeme@elasticsearch:9200/catalog'
-curl -XPOST 'http://elastic:changeme@elasticsearch:9200/catalog/dataset/_mapping' -d @./mappings.json
+curl -XPUT 'http://elastic:changeme@elasticsearch:9200/opal'
+curl -XPOST 'http://elastic:changeme@elasticsearch:9200/opal/dataset/_mapping' -d @./mappings.json