diff --git a/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsIntersector.java b/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsIntersector.java
index a54c5bf..a8b5fcb 100644
--- a/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsIntersector.java
+++ b/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsIntersector.java
@@ -13,7 +13,7 @@ public class OccurrencePointsIntersector extends OccurrencePointsMerger{
 	
 	@Override
 	public String getDescription() {
-		return "A transducer algorithm that produces a table of species occurrence points that are contained in both the two starting tables where points equivalence is identified via user defined comparison thresholds. Between two ocurrence sets, it keeps the elements of the Right Set that are similar to elements in the Left Set.";
+		return "A transducer algorithm that produces a table of species occurrence points that are contained in both the two starting tables where points equivalence is identified via user defined comparison thresholds. Works with up to 10000 points per table. Between two ocurrence sets, it keeps the elements of the Right Set that are similar to elements in the Left Set.";
 	}
 	
 	@Override
diff --git a/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsMerger.java b/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsMerger.java
index 5d11bec..cca1cfb 100644
--- a/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsMerger.java
+++ b/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsMerger.java
@@ -229,8 +229,8 @@ public class OccurrencePointsMerger implements Transducerer {
 		// occurrence points tables
 		PrimitiveType p0 = new PrimitiveType(String.class.getName(), null, PrimitiveTypes.STRING, finalTableNameL, "the name of the produced table", "Occ_");
 
-		InputTable p1 = new InputTable(templatesOccurrence, leftTableNameF, "the First table containing the occurrence points", "");
-		InputTable p2 = new InputTable(templatesOccurrence, rightTableNameF, "the Second table containing the occurrence points", "");
+		InputTable p1 = new InputTable(templatesOccurrence, leftTableNameF, "the First table containing the occurrence points (up to 10 000)", "");
+		InputTable p2 = new InputTable(templatesOccurrence, rightTableNameF, "the Second table containing the occurrence points (up to 10 000)", "");
 
 		// string parameters
 		ColumnType p3 = new ColumnType(leftTableNameF, longitudeColumn, "column with longitude values", "decimallongitude", false);
@@ -329,7 +329,7 @@ public class OccurrencePointsMerger implements Transducerer {
 
 	@Override
 	public String getDescription() {
-		return "A transducer algorithm that produces a duplicate-free table resulting from the union of two occurrence points tables where points equivalence is identified via user defined comparison thresholds. Between two Ocurrence Sets, enrichs the Left Set with the elements of the Right Set that are not in the Left Set. Updates the elements of the Left Set with more recent elements in the Right Set. If one element in the Left Set corresponds to several recent elements in the Right Set, these will be all substituted to the element of the Left Set.";
+		return "A transducer algorithm that produces a duplicate-free table resulting from the union of two occurrence points tables where points equivalence is identified via user defined comparison thresholds. Works with up to 10000 points per table. Between two Ocurrence Sets, enrichs the Left Set with the elements of the Right Set that are not in the Left Set. Updates the elements of the Left Set with more recent elements in the Right Set. If one element in the Left Set corresponds to several recent elements in the Right Set, these will be all substituted to the element of the Left Set.";
 	}
 
 	protected float probabilityStrings(String first, String second) {
@@ -576,10 +576,10 @@ public class OccurrencePointsMerger implements Transducerer {
 	public void takeFullRanges() {
 		// take the elements from sx table
 		AnalysisLogger.getLogger().info("Taking elements from left table: " + leftTableName);
-		leftRows = DatabaseFactory.executeSQLQuery(DatabaseUtils.getColumnsElementsStatement(leftTableName, columns.toString(), ""), dbconnection);
+		leftRows = DatabaseFactory.executeSQLQuery(DatabaseUtils.getColumnsElementsStatement(leftTableName, columns.toString(), " limit 10000"), dbconnection);
 		// take the elements from dx table
 		AnalysisLogger.getLogger().info("Taking elements from right table: " + rightTableName);
-		rightRows = DatabaseFactory.executeSQLQuery(DatabaseUtils.getColumnsElementsStatement(rightTableName, columns.toString(), ""), dbconnection);
+		rightRows = DatabaseFactory.executeSQLQuery(DatabaseUtils.getColumnsElementsStatement(rightTableName, columns.toString(), " limit 10000"), dbconnection);
 	}
 
 	public void takeRange(int offsetLeft, int numLeft, int offsetRight, int numRight) {
diff --git a/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsSubtraction.java b/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsSubtraction.java
index a06e64b..7c90467 100644
--- a/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsSubtraction.java
+++ b/src/main/java/org/gcube/dataanalysis/ecoengine/transducers/OccurrencePointsSubtraction.java
@@ -8,7 +8,7 @@ public class OccurrencePointsSubtraction extends OccurrencePointsMerger{
 	
 	@Override
 	public String getDescription() {
-		return "A transducer algorithm that produces a table resulting from the difference between two occurrence points tables where points equivalence is identified via user defined comparison thresholds. Between two Ocurrence Sets, keeps the elements of the Left Set that are not similar to any element in the Right Set.";
+		return "A transducer algorithm that produces a table resulting from the difference between two occurrence points tables where points equivalence is identified via user defined comparison thresholds. Works with up to 10000 points per table. Between two Ocurrence Sets, keeps the elements of the Left Set that are not similar to any element in the Right Set.";
 	}
 	
 	protected void manageHighProbability(float probability, OccurrenceRecord leftOcc, OccurrenceRecord rightOcc) {