diff --git a/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java b/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
index 3a4edce..2120ee2 100644
--- a/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
+++ b/src/main/java/eu/openaire/urls_controller/services/UrlsServiceImpl.java
@@ -118,15 +118,15 @@ public class UrlsServiceImpl implements UrlsService {
             "       join " + DatabaseConnector.databaseName + ".datasource d on d.id=p.datasourceid\n" +  // This is needed for the "d.allow_harvest=true" check later on.
             "       left outer join " + DatabaseConnector.databaseName + ".publication_boost pb\n" +
             "           on p.id=pb.id\n" +
-            "       left outer join (select count(a.id) as counts, a.id from " + DatabaseConnector.databaseName + ".attempt a group by a.id) as attempts\n" +
-            "           on attempts.id=p.id\n" +
-            "       left outer join (\n" +
-            "           select a.id, a.original_url from " + DatabaseConnector.databaseName + ".assignment a\n" +
+            "       left outer join (select count(at.original_url) as counts, at.original_url from " + DatabaseConnector.databaseName + ".attempt at group by at.original_url) as attempts\n" +
+            "           on attempts.original_url=pu.url\n" +
+            "       left anti join (\n" +
+            "           select a.original_url from " + DatabaseConnector.databaseName + ".assignment a\n" +
             "           union all\n" +
-            "           select pl.id, pl.original_url from " + DatabaseConnector.databaseName + ".payload pl\n" + // Here we access the payload-VIEW which includes the three payload-tables.
-            "           ) as existing\n" +
-            "               on existing.id=p.id and existing.original_url=pu.url\n" +
-            "   where d.allow_harvest=true and existing.id is null\n" + // For records not found on existing, the "existing.id" will be null.
+            "           select pl.original_url from " + DatabaseConnector.databaseName + ".payload pl\n" + // Here we access the payload-VIEW which includes the three payload-tables.
+            "       ) as existing\n" +
+            "           on existing.original_url=pu.url\n" +
+            "   where d.allow_harvest=true\n" +
                     ((excludedDatasourceIDsStringList != null) ?    // If we have an exclusion-list, use it below.
            ("       and d.id not in " + excludedDatasourceIDsStringList + "\n") : "") +
             "       and coalesce(attempts.counts, 0) <= " + maxAttemptsPerRecordAtomic.get() + "\n" +