diff --git a/modules/org.openbravo.advpaymentmngt/src/org/openbravo/advpaymentmngt/dao/AdvPaymentMngtDao.java b/modules/org.openbravo.advpaymentmngt/src/org/openbravo/advpaymentmngt/dao/AdvPaymentMngtDao.java
--- a/modules/org.openbravo.advpaymentmngt/src/org/openbravo/advpaymentmngt/dao/AdvPaymentMngtDao.java
+++ b/modules/org.openbravo.advpaymentmngt/src/org/openbravo/advpaymentmngt/dao/AdvPaymentMngtDao.java
@@ -259,7 +259,7 @@
       whereClause.append(" and (oinfo is null or oinfo.active = true)");
 
       // remove selected payments
-      if (selectedScheduledPaymentDetails != null && selectedScheduledPaymentDetails.size() > 0) {
+      if (selectedScheduledPaymentDetails != null && !selectedScheduledPaymentDetails.isEmpty()) {
         String strSelectedPaymentDetails = Utility.getInStrList(selectedScheduledPaymentDetails);
         whereClause.append(" and psd not in (");
         whereClause.append(strSelectedPaymentDetails);
@@ -270,9 +270,10 @@
       final OBCriteria<FIN_PaymentPropDetail> obc = OBDal.getInstance().createCriteria(
           FIN_PaymentPropDetail.class);
       obc.add(Restrictions.isNotNull(FIN_PaymentPropDetail.PROPERTY_FINPAYMENTSCHEDULEDETAIL));
-      if (obc.list() != null && obc.list().size() > 0) {
+      List<FIN_PaymentPropDetail> paymentPropDetailList = obc.list();
+      if (!paymentPropDetailList.isEmpty()) {
         List<FIN_PaymentScheduleDetail> aux = new ArrayList<FIN_PaymentScheduleDetail>();
-        for (FIN_PaymentPropDetail ppd : obc.list()) {
+        for (FIN_PaymentPropDetail ppd : paymentPropDetailList) {
           aux.add(ppd.getFINPaymentScheduledetail());
         }
         whereClause.append(" and psd.id not in (" + Utility.getInStrList(aux) + ")");
@@ -1153,7 +1154,7 @@
           FIN_FinaccTransaction.class, whereClause.toString());
       obqFATrx.setFirstResult(offset);
       obqFATrx.setMaxResult(maxrowspergridpage);
-      return obqFATrx.list().size();
+      return obqFATrx.count();
 
     } finally {
       OBContext.restorePreviousMode();
@@ -1545,28 +1546,30 @@
     }
     obc.addOrder(org.hibernate.criterion.Order.asc("pm." + FIN_PaymentMethod.PROPERTY_NAME));
     obc.setFilterOnReadableOrganization(false);
-    List<FinAccPaymentMethod> defaults = obc.list();
-    if (defaults.size() > 0) {
-      return obc.list().get(0).getPaymentMethod().getId();
+    obc.setMaxResults(1);
+    FinAccPaymentMethod paymentMethod = (FinAccPaymentMethod) obc.uniqueResult();
+    if (paymentMethod != null) {
+      return paymentMethod.getPaymentMethod().getId();
     } else {
       return "";
     }
   }
 
   private void addPaymentMethodList(OBCriteria<FIN_PaymentMethod> obc, List<String> paymentMethods) {
-    List<String> paymentMethodsToRemove;
     Criterion compoundExp = null;
-    while (paymentMethods.size() > 999) {
-      paymentMethodsToRemove = new ArrayList<String>(paymentMethods.subList(0, 999));
+    int paymentMethodsSize = paymentMethods.size();
+    while (paymentMethodsSize > 999) {
+      List<String> paymentMethodsToRemove = paymentMethods.subList(0, 999);
       if (compoundExp == null) {
-        compoundExp = Restrictions.in("id", paymentMethods.subList(0, 999));
+        compoundExp = Restrictions.in("id", paymentMethodsToRemove);
       } else {
         compoundExp = Restrictions.or(compoundExp,
             Restrictions.in("id", paymentMethods.subList(0, 999)));
       }
       paymentMethods.removeAll(paymentMethodsToRemove);
+      paymentMethodsSize = paymentMethodsSize - 999;
     }
-    if (paymentMethods.size() > 0) {
+    if (paymentMethodsSize > 0) {
       if (compoundExp == null) {
         compoundExp = Restrictions.in("id", paymentMethods);
       } else {
@@ -1676,14 +1679,14 @@
     }
 
     public Criterion getCriterion() {
-      if (finAccs.size() > 0) {
+      if (!finAccs.isEmpty()) {
         refresh();
       }
       return compoundexp;
     }
 
     private void refresh() {
-      // finAccs.size() must be > 0
+      // finAccs size must be > 0
       if (compoundexp == null) {
         compoundexp = Restrictions.in("id", finAccs);
       } else {
@@ -1879,9 +1882,10 @@
     OBCriteria<APRMPendingPaymentFromInvoice> ppfiCriteria = OBDal.getInstance().createCriteria(
         APRMPendingPaymentFromInvoice.class);
     ppfiCriteria.add(Restrictions.eq(APRMPendingPaymentFromInvoice.PROPERTY_PAYMENT, payment));
-    List<APRMPendingPaymentFromInvoice> pendingPayments = ppfiCriteria.list();
-    if (pendingPayments != null && pendingPayments.size() > 0) {
-      APRMPendingPaymentFromInvoice pendingPayment = pendingPayments.get(0);
+    ppfiCriteria.setMaxResults(1);
+    APRMPendingPaymentFromInvoice pendingPayment = (APRMPendingPaymentFromInvoice) ppfiCriteria
+        .uniqueResult();
+    if (pendingPayment != null) {
       pendingPayment.setProcessNow(executing);
       OBDal.getInstance().flush();
       OBDal.getInstance().save(pendingPayment);
@@ -1892,12 +1896,14 @@
     OBCriteria<APRMPendingPaymentFromInvoice> ppfiCriteria = OBDal.getInstance().createCriteria(
         APRMPendingPaymentFromInvoice.class);
     ppfiCriteria.add(Restrictions.eq(APRMPendingPaymentFromInvoice.PROPERTY_PAYMENT, payment));
-    List<APRMPendingPaymentFromInvoice> pendingPayments = ppfiCriteria.list();
-    if (pendingPayments != null && pendingPayments.size() > 0) {
-      return pendingPayments.get(0).isProcessNow();
-    } else
+    ppfiCriteria.setMaxResults(1);
+    APRMPendingPaymentFromInvoice pendingPayment = (APRMPendingPaymentFromInvoice) ppfiCriteria
+        .uniqueResult();
+    if (pendingPayment != null) {
+      return pendingPayment.isProcessNow();
+    } else {
       return false;
-
+    }
   }
 
   public void removeFromExecutionPending(FIN_Payment payment) {
@@ -2047,15 +2053,9 @@
     obc.add(Restrictions.in("organization.id", OBContext.getOBContext()
         .getOrganizationStructureProvider().getNaturalTree(strOrgId)));
     obc.setFilterOnReadableOrganization(false);
-
     obc.add(Restrictions.eq(FIN_FinancialAccount.PROPERTY_DEFAULT, true));
-
-    final List<FIN_FinancialAccount> defaultAccounts = obc.list();
-    if (defaultAccounts.size() > 0) {
-      return defaultAccounts.get(0);
-    } else {
-      return null;
-    }
+    obc.setMaxResults(1);
+    return (FIN_FinancialAccount) obc.uniqueResult();
   }
 
   public boolean existsAPRMReadyPreference() {
@@ -2111,13 +2111,7 @@
           .getOrganizationStructureProvider().getNaturalTree(organization.getId())));
       obcFinPayment.addOrderBy(FIN_Payment.PROPERTY_PAYMENTDATE, true);
       obcFinPayment.setMaxResults(1);
-
-      final List<FIN_Payment> finPayments = obcFinPayment.list();
-      if (finPayments.size() > 0) {
-        return finPayments.get(0);
-      } else {
-        return null;
-      }
+      return (FIN_Payment) obcFinPayment.uniqueResult();
     } finally {
       OBContext.restorePreviousMode();
     }
diff --git a/modules/org.openbravo.advpaymentmngt/src/org/openbravo/advpaymentmngt/dao/TransactionsDao.java b/modules/org.openbravo.advpaymentmngt/src/org/openbravo/advpaymentmngt/dao/TransactionsDao.java
--- a/modules/org.openbravo.advpaymentmngt/src/org/openbravo/advpaymentmngt/dao/TransactionsDao.java
+++ b/modules/org.openbravo.advpaymentmngt/src/org/openbravo/advpaymentmngt/dao/TransactionsDao.java
@@ -83,9 +83,7 @@
           FIN_FinaccTransaction.class, whereClause.toString());
       obQuery.setParameters(parameters);
       OBObjectFieldProvider[] objectFieldProvider = null;
-      if (obQuery != null && obQuery.list().size() > 0) {
-        objectFieldProvider = OBObjectFieldProvider.createOBObjectFieldProvider(obQuery.list());
-      }
+      objectFieldProvider = OBObjectFieldProvider.createOBObjectFieldProvider(obQuery.list());
       return objectFieldProvider;
     } finally {
       OBContext.restorePreviousMode();
@@ -216,10 +214,7 @@
       obc.addOrderBy(FIN_Reconciliation.PROPERTY_ENDINGDATE, false);
       obc.addOrderBy(FIN_Reconciliation.PROPERTY_CREATIONDATE, false);
       obc.setMaxResults(1);
-      final List<FIN_Reconciliation> rec = obc.list();
-      if (rec.size() == 0)
-        return null;
-      return rec.get(0);
+      return (FIN_Reconciliation) obc.uniqueResult();
     } finally {
       OBContext.restorePreviousMode();
     }
@@ -240,7 +235,7 @@
           .append(" is null ");
       final OBQuery<FIN_FinaccTransaction> obqFATrx = OBDal.getInstance().createQuery(
           FIN_FinaccTransaction.class, whereClause.toString());
-      return obqFATrx.list().size();
+      return obqFATrx.count();
 
     } finally {
       OBContext.restorePreviousMode();
@@ -262,14 +257,11 @@
   }
 
   public static Period getPeriod(Date date) {
-    Period period = null;
     OBCriteria<Period> obcPe = OBDal.getInstance().createCriteria(Period.class);
     obcPe.add(Restrictions.le(Period.PROPERTY_ENDINGDATE, date));
     obcPe.add(Restrictions.ge(Period.PROPERTY_STARTINGDATE, date));
-    if (obcPe.list() != null && obcPe.list().size() > 0) {
-      period = obcPe.list().get(0);
-    }
-    return period;
+    obcPe.setMaxResults(1);
+    return (Period) obcPe.uniqueResult();
   }
 
   public static List<FIN_FinaccTransaction> getTransactionsToReconciled(
diff --git a/src-test/src/org/openbravo/test/costing/TestCosting.java b/src-test/src/org/openbravo/test/costing/TestCosting.java
--- a/src-test/src/org/openbravo/test/costing/TestCosting.java
+++ b/src-test/src/org/openbravo/test/costing/TestCosting.java
@@ -10269,7 +10269,7 @@
     try {
       final OBCriteria<Product> criteria = OBDal.getInstance().createCriteria(Product.class);
       criteria.add(Restrictions.like(Product.PROPERTY_NAME, name + "-%"));
-      return criteria.list().size();
+      return criteria.count();
     } catch (Exception e) {
       throw new OBException(e);
     }
diff --git a/src-test/src/org/openbravo/test/inventoryStatus/InventoryStatusTest.java b/src-test/src/org/openbravo/test/inventoryStatus/InventoryStatusTest.java
--- a/src-test/src/org/openbravo/test/inventoryStatus/InventoryStatusTest.java
+++ b/src-test/src/org/openbravo/test/inventoryStatus/InventoryStatusTest.java
@@ -593,7 +593,7 @@
     try {
       final OBCriteria<Locator> criteria = OBDal.getInstance().createCriteria(Locator.class);
       criteria.add(Restrictions.like(Locator.PROPERTY_SEARCHKEY, searchKey + "-%"));
-      return criteria.list().size();
+      return criteria.count();
     } catch (Exception e) {
       throw new OBException(e);
     }
@@ -647,7 +647,7 @@
     try {
       final OBCriteria<Product> criteria = OBDal.getInstance().createCriteria(Product.class);
       criteria.add(Restrictions.like(Product.PROPERTY_NAME, name + "-%"));
-      return criteria.list().size();
+      return criteria.count();
     } catch (Exception e) {
       throw new OBException(e);
     }
@@ -723,7 +723,7 @@
       final OBCriteria<ShipmentInOut> criteria = OBDal.getInstance().createCriteria(
           ShipmentInOut.class);
       criteria.add(Restrictions.like(ShipmentInOut.PROPERTY_DOCUMENTNO, docNo + "-%"));
-      return criteria.list().size();
+      return criteria.count();
     } catch (Exception e) {
       throw new OBException(e);
     }
diff --git a/src/org/openbravo/erpCommon/ad_callouts/SE_Invoice_BPartner.java b/src/org/openbravo/erpCommon/ad_callouts/SE_Invoice_BPartner.java
--- a/src/org/openbravo/erpCommon/ad_callouts/SE_Invoice_BPartner.java
+++ b/src/org/openbravo/erpCommon/ad_callouts/SE_Invoice_BPartner.java
@@ -253,7 +253,7 @@
           obc.add(Restrictions.in(FinAccPaymentMethod.PROPERTY_ORGANIZATION + ".id", OBContext
               .getOBContext().getOrganizationStructureProvider().getNaturalTree(strOrgId)));
 
-          // filter is on unique constraint so list().size() <=1 always
+          // filter is on unique constraint so list size <=1 always
           if (obc.uniqueResult() == null) {
             message = Utility.messageBD(this, "PaymentmethodNotbelongsFinAccount",
                 vars.getLanguage());
diff --git a/src/org/openbravo/erpCommon/ad_callouts/SE_Locator_Activate.java b/src/org/openbravo/erpCommon/ad_callouts/SE_Locator_Activate.java
--- a/src/org/openbravo/erpCommon/ad_callouts/SE_Locator_Activate.java
+++ b/src/org/openbravo/erpCommon/ad_callouts/SE_Locator_Activate.java
@@ -100,7 +100,8 @@
     final OBQuery<StorageDetail> query = OBDal.getInstance().createQuery(StorageDetail.class,
         hsqlScript.toString());
     query.setParameters(parameters);
-    return query.list().size() > 0;
+    query.setMaxResult(1);
+    return query.uniqueResult() != null;
   }
 
   /**
@@ -124,7 +125,8 @@
     final OBQuery<StoragePending> query = OBDal.getInstance().createQuery(StoragePending.class,
         hsqlScript.toString());
     query.setParameters(parameters);
-    return query.list().size() > 0;
+    query.setMaxResult(1);
+    return query.uniqueResult() != null;
   }
 
   /**
diff --git a/src/org/openbravo/erpCommon/utility/InventoryStatusUtils.java b/src/org/openbravo/erpCommon/utility/InventoryStatusUtils.java
--- a/src/org/openbravo/erpCommon/utility/InventoryStatusUtils.java
+++ b/src/org/openbravo/erpCommon/utility/InventoryStatusUtils.java
@@ -124,7 +124,7 @@
     obc.add(Restrictions.eq(Locator.PROPERTY_ISVIRTUAL, true));
     obc.add(Restrictions.eq(Locator.PROPERTY_PARENTLOCATOR, storageBin));
     obc.setFilterOnActive(active);
-    return obc.list().size();
+    return obc.count();
   }
 
   /**
diff --git a/src/org/openbravo/erpCommon/utility/Utility.java b/src/org/openbravo/erpCommon/utility/Utility.java
--- a/src/org/openbravo/erpCommon/utility/Utility.java
+++ b/src/org/openbravo/erpCommon/utility/Utility.java
@@ -1844,9 +1844,11 @@
         + "  and rlt.language.language = '" + lang + "'" + "  and r.name =  '" + ListName + "'"
         + "  and rl.searchKey = '" + value + "'";
     Query q = OBDal.getInstance().getSession().createQuery(hql);
+    q.setMaxResults(1);
 
-    if (q.list().size() > 0) {
-      return (String) q.list().get(0);
+    String name = (String) q.uniqueResult();
+    if (name != null) {
+      return name;
     }
 
     // No translated value obtained, get the standard one
@@ -1854,9 +1856,11 @@
         + " where rl.reference = r" + "  and r.name =  '" + ListName + "'"
         + "  and rl.searchKey = '" + value + "'";
     q = OBDal.getInstance().getSession().createQuery(hql);
+    q.setMaxResults(1);
 
-    if (q.list().size() > 0) {
-      return (String) q.list().get(0);
+    name = (String) q.uniqueResult();
+    if (name != null) {
+      return name;
     } else {
       // Nothing found, return the value
       return value;