diff --git a/defaults/yacy.init b/defaults/yacy.init
index ae70b9162..25769d1a8 100644
--- a/defaults/yacy.init
+++ b/defaults/yacy.init
@@ -442,6 +442,7 @@ seedScpPath=
 peerCycle=2
 
 # debug flags
+debug.search.profiling=false
 debug.search.local.dht.off=false
 debug.search.local.solr.off=false
 debug.search.remote.dht.off=false
diff --git a/source/net/yacy/cora/federate/solr/connector/EmbeddedSolrConnector.java b/source/net/yacy/cora/federate/solr/connector/EmbeddedSolrConnector.java
index 10d36a9c9..7b5c104d5 100644
--- a/source/net/yacy/cora/federate/solr/connector/EmbeddedSolrConnector.java
+++ b/source/net/yacy/cora/federate/solr/connector/EmbeddedSolrConnector.java
@@ -30,6 +30,7 @@ import java.util.concurrent.LinkedBlockingQueue;
 import net.yacy.cora.federate.solr.instance.EmbeddedInstance;
 import net.yacy.cora.federate.solr.instance.SolrInstance;
 import net.yacy.cora.util.ConcurrentLog;
+import net.yacy.search.Switchboard;
 import net.yacy.search.schema.CollectionSchema;
 
 import org.apache.lucene.document.Document;
@@ -245,6 +246,17 @@ public class EmbeddedSolrConnector extends SolrServerConnector implements SolrCo
     
     @Override
     public Set<String> existsByIds(Set<String> ids) {
+        boolean debug = Switchboard.getSwitchboard().getConfigBool("debug.search.profiling", false);
+        long debugSingleTime = 0; int debugSingleCount = 0;
+        if (debug) {
+            // run this also with single exist queries which might be faster (but we don't know, thats the reason we test that here)
+            long start = System.currentTimeMillis();
+            Set <String> idsr = new HashSet<String>();
+            for (String id: ids) if (existsById(id)) idsr.add(id);
+            debugSingleTime = System.currentTimeMillis() - start;
+            debugSingleCount = idsr.size();
+        }
+        long start = System.currentTimeMillis();
         if (ids == null || ids.size() == 0) return new HashSet<String>();
         if (ids.size() == 1) return existsById(ids.iterator().next()) ? ids : new HashSet<String>();
         StringBuilder sb = new StringBuilder(); // construct something like "({!raw f=id}Ij7B63g-gSHA) OR ({!raw f=id}PBcGI3g-gSHA)"
@@ -267,6 +279,10 @@ public class EmbeddedSolrConnector extends SolrServerConnector implements SolrCo
         } finally {
             docListSearcher.close();
         }
+        long debugCollectionTime = System.currentTimeMillis() - start;
+        if (debug) {
+            ConcurrentLog.info("EmbeddedSolrConnector", "Comparisment of existsByIds: input=" + ids.size() + " records, output=" + idsr.size() + " records, singleTime=" + debugSingleTime + ", collectionTime=" + debugCollectionTime + ", singleCount=" + debugSingleCount + ", collectionCount=" + idsr.size());
+        }
         // construct a new id list from that
         return idsr;
     }