diff --git a/src/main/java/org/gcube/dataaccess/databases/utils/DatabaseOperations.java b/src/main/java/org/gcube/dataaccess/databases/utils/DatabaseOperations.java
index 4bd16b4..3de5332 100644
--- a/src/main/java/org/gcube/dataaccess/databases/utils/DatabaseOperations.java
+++ b/src/main/java/org/gcube/dataaccess/databases/utils/DatabaseOperations.java
@@ -21,19 +21,24 @@ public class DatabaseOperations {
 
 	// private static final String QueryPostgres =
 	// "select count(*) from \"%1$s\" limit 1";
-//	private static final String QueryPostgres = "select count(*) from (select * from \"%1$s\" limit 1) as a";
+	// private static final String QueryPostgres =
+	// "select count(*) from (select * from \"%1$s\" limit 1) as a";
 	private static final String QueryPostgres = "select count(*) from (select * from %1$s limit 1) as a";
-//	private static final String QueryMysql = "select count(*) from (select * from `%1$s` limit 1) as a";
+	// private static final String QueryMysql =
+	// "select count(*) from (select * from `%1$s` limit 1) as a";
 	private static final String QueryMysql = "select count(*) from (select * from %1$s limit 1) as a";
 	// private static final String QueryMysql =
 	// "select count(*) from `%1$s` limit 1";
+	private static final String ActualRowsNumberQueryPostgres = "select count(*) from (select * from %1$s) as a";
 
 	// private static final String Query = "select * from %1$s limit 1";
 	// private static final String countQuery = "select count(*) from %1$s";
 	// private static final String explainQuery = "explain select * from %1$s";
-//	private static final String explainQueryPostgres = "explain select * from \"%1$s\"";
+	// private static final String explainQueryPostgres =
+	// "explain select * from \"%1$s\"";
 	private static final String explainQueryPostgres = "explain select * from %1$s";
-//	private static final String explainQueryMysql = "explain select * from `%1$s`";
+	// private static final String explainQueryMysql =
+	// "explain select * from `%1$s`";
 	private static final String explainQueryMysql = "explain select * from %1$s";
 
 	private static final String MYSQL = "MySQL";
@@ -105,154 +110,185 @@ public class DatabaseOperations {
 		return DBType;
 
 	}
-	
+
 	// Method that calculate the estimated number of rows
-		public long calculateElements(ConnectionManager connection,
-				String dbType, String tablename, String schemaName, SessionFactory session)
-				throws Exception {
+	public long calculateElements(ConnectionManager connection, String dbType,
+			String tablename, String schemaName, SessionFactory session)
+			throws Exception {
 
-			long count = 0;
+		long count = 0;
 
-			String countingQuery = null;
+		String countingQuery = null;
 
-			if (dbType.equals(POSTGRES)) {
-				
-				//the full name equal to "schemaname.tablename"
-				tablename=schemaName+"."+ "\"" +tablename+ "\"";
+		if (dbType.equals(POSTGRES)) {
 
-				countingQuery = String.format(QueryPostgres, tablename);
+			// the full name equal to "schemaname.tablename"
+			tablename = schemaName + "." + "\"" + tablename + "\"";
 
-			}
-			if (dbType.equals(MYSQL)) {
-				//the full name equal to "dbname.tablename"
-				tablename=schemaName+"."+tablename;
+			countingQuery = String.format(QueryPostgres, tablename);
 
-				countingQuery = String.format(QueryMysql, tablename);
+		}
+		if (dbType.equals(MYSQL)) {
+			// the full name equal to "dbname.tablename"
+			tablename = schemaName + "." + tablename;
 
-			}
+			countingQuery = String.format(QueryMysql, tablename);
 
-			AnalysisLogger.getLogger().debug(
-					"DatabaseOperations->calculating rows' number with the query: "
-							+ countingQuery);
+		}
 
-			List<Object> result;
+		AnalysisLogger.getLogger().debug(
+				"DatabaseOperations->calculating rows' number with the query: "
+						+ countingQuery);
 
-			// try {
-			// result = DatabaseFactory.executeSQLQuery(countingQuery, session);
+		List<Object> result;
 
-			result = connection.executeQuery(countingQuery, session);
+		// try {
+		// result = DatabaseFactory.executeSQLQuery(countingQuery, session);
 
-			// if ((result != null) && (result.size() > 0)) {
-			if (result != null) {
-				
-				Object element = result.get(0);
-				
-				ArrayList<Object> listvalues = new ArrayList<Object>(((LinkedHashMap<String, Object>) element).values());
-				
-				
+		result = connection.executeQuery(countingQuery, session);
 
-				// System.out.println("Dimension: " + result.size());
+		// if ((result != null) && (result.size() > 0)) {
+		if (result != null) {
 
-//				Integer numElem = Integer.valueOf(result.get(0).toString());
-				
-//				Long numElemvalue = Long.valueOf(result.get(0).toString());
-				
-				Long numElemvalue = Long.valueOf(listvalues.get(0).toString());
-				
-				long numElem  = numElemvalue.longValue();
+			Object element = result.get(0);
 
-				// if (numElem.intValue() == 0){ throw new
-				// Exception("The table has not rows");}
+			ArrayList<Object> listvalues = new ArrayList<Object>(
+					((LinkedHashMap<String, Object>) element).values());
 
-				if (numElem > 0) {
+			// System.out.println("Dimension: " + result.size());
 
-					AnalysisLogger
-							.getLogger()
-							.debug("DatabaseOperations->the database has at least a row.Calculating rows' number through an estimation");
+			// Integer numElem = Integer.valueOf(result.get(0).toString());
 
-					String explain = null;
+			// Long numElemvalue = Long.valueOf(result.get(0).toString());
 
-					if (dbType.equals(POSTGRES)) {
-						
+			Long numElemvalue = Long.valueOf(listvalues.get(0).toString());
 
-						explain = String.format(explainQueryPostgres, tablename);
+			long numElem = numElemvalue.longValue();
 
-					}
-					if (dbType.equals(MYSQL)) {
-						
-						
-						explain = String.format(explainQueryMysql, tablename);
+			// if (numElem.intValue() == 0){ throw new
+			// Exception("The table has not rows");}
 
-					}
+			if (numElem > 0) {
 
-					// call query with explain function
+				AnalysisLogger
+						.getLogger()
+						.debug("DatabaseOperations->the database has at least a row.Calculating rows' number through an estimation");
 
+				String explain = null;
+
+				if (dbType.equals(POSTGRES)) {
+
+					explain = String.format(explainQueryPostgres, tablename);
+
+				}
+				if (dbType.equals(MYSQL)) {
+
+					explain = String.format(explainQueryMysql, tablename);
+
+				}
+
+				// call query with explain function
+
+				AnalysisLogger.getLogger().debug(
+						"DatabaseOperations->calculating rows' number with the query: "
+								+ explain);
+
+				List<Object> resultinfo;
+
+				// resultinfo = DatabaseFactory.executeSQLQuery(explain,
+				// session);
+
+				resultinfo = connection.executeQuery(explain, session);
+
+				// recovery result
+
+				if (dbType.equals(MYSQL)) {
+
+					// Object[] resultArray = (Object[]) (resultinfo.get(0));
+
+					Object elem = resultinfo.get(0);
+
+					ArrayList<Object> values = new ArrayList<Object>(
+							((LinkedHashMap<String, Object>) elem).values());
+
+					// //print check
+					// AnalysisLogger.getLogger().debug(
+					// "DatabaseOperations->VALUE: " + values);
+
+					BigInteger value = (BigInteger) values.get(8);
+
+					// BigInteger value = (BigInteger) resultArray[8];
+
+					count = value.longValue();
+
+				}
+
+				if (dbType.equals(POSTGRES)) {
+
+					String var = resultinfo.get(0).toString();
+
+					int beginindex = var.indexOf("rows");
+
+					int lastindex = var.indexOf("width");
+
+					var = var.substring(beginindex + 5, lastindex - 1);
+
+					Long value = Long.valueOf(var);
+
+					count = value.longValue();
+					
 					AnalysisLogger.getLogger().debug(
-							"DatabaseOperations->calculating rows' number with the query: "
-									+ explain);
+							"DatabaseOperations-> rows' number with explain function: "
+									+ count);
 
-					List<Object> resultinfo;
+					// threshold fixed to 100000 value in order to count an
+					// actual rows' number if the estimated rows is < 100000
+					// otherwise because PGAdmin returns a wrong rows number for
+					// a table with a little rows number.
 
-					// resultinfo = DatabaseFactory.executeSQLQuery(explain,
-					// session);
+					if (count < 100000) {
+						AnalysisLogger.getLogger().debug(
+								"DatabaseOperations->rows' number with explain function less than the threshold with value 100000");
+						// to count an actual rows number
+						AnalysisLogger.getLogger().debug(
+								"DatabaseOperations->calculating the actual rows' number with the query: "
+										+ String.format(
+												ActualRowsNumberQueryPostgres,
+												tablename));
 
-					resultinfo = connection.executeQuery(explain, session);
+						List<Object> resultRowsNumber;
+						resultRowsNumber = connection.executeQuery(String
+								.format(ActualRowsNumberQueryPostgres,
+										tablename), session);
 
-					// recovery result
-
-					if (dbType.equals(MYSQL)) {
-
-//						Object[] resultArray = (Object[]) (resultinfo.get(0));
-						
-						Object elem = resultinfo.get(0);
-						
-						ArrayList<Object> values = new ArrayList<Object>(
-								((LinkedHashMap<String, Object>) elem).values());
-						
-//                      //print check
-//						AnalysisLogger.getLogger().debug(
-//								"DatabaseOperations->VALUE: " + values);
-						
-						BigInteger value = (BigInteger) values.get(8);
-
-//						BigInteger value = (BigInteger) resultArray[8];
-						
-						count = value.longValue();
-						
-						
-
-					}
-
-					if (dbType.equals(POSTGRES)) {
-
-						String var = resultinfo.get(0).toString();
-
-						int beginindex = var.indexOf("rows");
-
-						int lastindex = var.indexOf("width");
-
-						var = var.substring(beginindex + 5, lastindex - 1);
-						
-						Long value = Long.valueOf(var);
-
-						count = value.longValue();
+						if (resultRowsNumber != null) {
+							Object elem = resultRowsNumber.get(0);
+							ArrayList<Object> listValues = new ArrayList<Object>(
+									((LinkedHashMap<String, Object>) elem)
+											.values());
+							Long numElemValue = Long.valueOf(listValues.get(0)
+									.toString());
+							count = numElemValue.longValue();
 
+						}
 					}
 
 				}
 
 			}
 
-			// } catch (Exception e) {
-			// TODO Auto-generated catch block
-			// e.printStackTrace();
-			// }
-
-			AnalysisLogger.getLogger().debug(
-					"DatabaseOperations->rows' number calculated: " + count);
-
-			return count;
-
 		}
 
+		// } catch (Exception e) {
+		// TODO Auto-generated catch block
+		// e.printStackTrace();
+		// }
+
+		AnalysisLogger.getLogger().debug(
+				"DatabaseOperations->rows' number calculated: " + count);
+
+		return count;
+
+	}
+
 }