diff --git a/dhp-workflows/dhp-enrichment/src/main/java/eu/dnetlib/dhp/resulttocommunityfromorganization/PrepareResultCommunitySet.java b/dhp-workflows/dhp-enrichment/src/main/java/eu/dnetlib/dhp/resulttocommunityfromorganization/PrepareResultCommunitySet.java
index 1a008797da..19b9859648 100644
--- a/dhp-workflows/dhp-enrichment/src/main/java/eu/dnetlib/dhp/resulttocommunityfromorganization/PrepareResultCommunitySet.java
+++ b/dhp-workflows/dhp-enrichment/src/main/java/eu/dnetlib/dhp/resulttocommunityfromorganization/PrepareResultCommunitySet.java
@@ -9,7 +9,9 @@ import java.util.*;
 import org.apache.commons.io.IOUtils;
 import org.apache.hadoop.io.compress.GzipCodec;
 import org.apache.spark.SparkConf;
+import org.apache.spark.api.java.function.FilterFunction;
 import org.apache.spark.api.java.function.MapFunction;
+import org.apache.spark.api.java.function.MapGroupsFunction;
 import org.apache.spark.sql.Dataset;
 import org.apache.spark.sql.Encoders;
 import org.apache.spark.sql.SparkSession;
@@ -70,28 +72,33 @@ public class PrepareResultCommunitySet {
 		String outputPath,
 		OrganizationMap organizationMap) {
 
-		Dataset<Relation> relation = readPath(spark, inputPath, Relation.class);
-		relation.createOrReplaceTempView("relation");
+		Dataset<Relation> relationAffiliation = readPath(spark, inputPath, Relation.class)
+			.filter(
+				(FilterFunction<Relation>) r -> !r.getDataInfo().getDeletedbyinference() &&
+					r.getRelClass().equalsIgnoreCase(ModelConstants.HAS_AUTHOR_INSTITUTION));
 
-		String query = "SELECT result_organization.source resultId, result_organization.target orgId, org_set merges "
-			+ "FROM (SELECT source, target "
-			+ "      FROM relation "
-			+ "      WHERE datainfo.deletedbyinference = false "
-			+ "      AND lower(relClass) = '"
-			+ ModelConstants.HAS_AUTHOR_INSTITUTION.toLowerCase()
-			+ "') result_organization "
-			+ "LEFT JOIN (SELECT source, collect_set(target) org_set "
-			+ "      FROM relation "
-			+ "      WHERE datainfo.deletedbyinference = false "
-			+ "      AND lower(relClass) = '"
-			+ ModelConstants.MERGES.toLowerCase()
-			+ "' "
-			+ "      GROUP BY source) organization_organization "
-			+ "ON result_organization.target = organization_organization.source ";
+		Dataset<Relation> relationOrganization = readPath(spark, inputPath, Relation.class)
+			.filter(
+				(FilterFunction<Relation>) r -> !r.getDataInfo().getDeletedbyinference() &&
+					r.getRelClass().equalsIgnoreCase(ModelConstants.MERGES));
 
-		Dataset<ResultOrganizations> result_organizationset = spark
-			.sql(query)
-			.as(Encoders.bean(ResultOrganizations.class));
+		Dataset<ResultOrganizations> result_organizationset = relationAffiliation
+			.joinWith(
+				relationOrganization,
+				relationAffiliation.col("target").equalTo(relationOrganization.col("source")),
+				"left")
+			.groupByKey((MapFunction<Tuple2<Relation, Relation>, String>) t2 -> t2._2().getSource(), Encoders.STRING())
+			.mapGroups((MapGroupsFunction<String, Tuple2<Relation, Relation>, ResultOrganizations>) (k, it) -> {
+				ResultOrganizations rOrgs = new ResultOrganizations();
+				rOrgs.setOrgId(k);
+				Tuple2<Relation, Relation> first = it.next();
+				rOrgs.setResultId(first._1().getSource());
+				ArrayList<String> merges = new ArrayList<>();
+				merges.add(first._2().getTarget());
+				it.forEachRemaining(t -> merges.add(t._2().getTarget()));
+				rOrgs.setMerges(merges);
+				return rOrgs;
+			}, Encoders.bean(ResultOrganizations.class));
 
 		result_organizationset
 			.map(mapResultCommunityFn(organizationMap), Encoders.bean(ResultCommunityList.class))