Index: Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/HydraRingDatabaseParseHelper.cs
===================================================================
diff -u -re73c8b159778b281ecb275512f42da65c0d02e9d -r648d6c8d5c952943c3f428981f97c1cdd8b0bd37
--- Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/HydraRingDatabaseParseHelper.cs	(.../HydraRingDatabaseParseHelper.cs)	(revision e73c8b159778b281ecb275512f42da65c0d02e9d)
+++ Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/HydraRingDatabaseParseHelper.cs	(.../HydraRingDatabaseParseHelper.cs)	(revision 648d6c8d5c952943c3f428981f97c1cdd8b0bd37)
@@ -71,7 +71,7 @@
         /// <param name="exceptionMessage">The message to use in the exception when reading fails.</param>
         /// <param name="reader">The reader to read a row from.</param>
         /// <returns>A single row from the reader.</returns>
-        /// <exception cref="HydraRingFileParserException">Thrown when no row could be read from the reader
+        /// <exception cref="HydraRingFileParserException">Thrown when no row could be read from the
         /// <paramref name="reader"/>.</exception>
         private static Dictionary<string, object> ReadLineFromReader(string exceptionMessage, HydraRingDatabaseReader reader)
         {
Index: Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/FaultTreeIllustrationPoint.cs
===================================================================
diff -u -r288827a5a3e825d8e47cff85d76495e2601483f1 -r648d6c8d5c952943c3f428981f97c1cdd8b0bd37
--- Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/FaultTreeIllustrationPoint.cs	(.../FaultTreeIllustrationPoint.cs)	(revision 288827a5a3e825d8e47cff85d76495e2601483f1)
+++ Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/FaultTreeIllustrationPoint.cs	(.../FaultTreeIllustrationPoint.cs)	(revision 648d6c8d5c952943c3f428981f97c1cdd8b0bd37)
@@ -24,7 +24,7 @@
 namespace Ringtoets.HydraRing.Calculation.Parsers.IllustrationPoints
 {
     /// <summary>
-    /// An illustration points which uses the results of two sub illustration points
+    /// An illustration point which uses the results of two sub illustration points
     /// to obtain a result.
     /// </summary>
     public class FaultTreeIllustrationPoint : IIllustrationPoint
@@ -45,9 +45,9 @@
         public double Beta { get; set; } = double.NaN;
         
         /// <summary>
-        /// The way in which the sub illustartion points are combined to
+        /// The way in which the sub illustration points are combined to
         /// obtain a result for the fault tree illustration point.
         /// </summary>
-        public CombinationType Combine { get; set; }
+        public CombinationType CombinationType { get; set; }
     }
 }
\ No newline at end of file
Index: Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/IllustrationPointQueries.cs
===================================================================
diff -u -r288827a5a3e825d8e47cff85d76495e2601483f1 -r648d6c8d5c952943c3f428981f97c1cdd8b0bd37
--- Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/IllustrationPointQueries.cs	(.../IllustrationPointQueries.cs)	(revision 288827a5a3e825d8e47cff85d76495e2601483f1)
+++ Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/IllustrationPointQueries.cs	(.../IllustrationPointQueries.cs)	(revision 648d6c8d5c952943c3f428981f97c1cdd8b0bd37)
@@ -26,12 +26,15 @@
     /// </summary>
     public static class IllustrationPointQueries
     {
+        private const string firstPeriod = "PeriodId = (SELECT MIN(PeriodId) FROM DesignPointResults)";
+        private const string lastIteration = "OuterIterationId = (SELECT MAX(OuterIterationId) FROM DesignPointResults)";
+
         /// <summary>
         /// Selects all the closing situations.
         /// </summary>
         public static readonly string ClosingSituations =
             $"SELECT {IllustrationPointsDatabaseConstants.ClosingSituationId}, " +
-            "ClosingSituationName " +
+            $"{IllustrationPointsDatabaseConstants.ClosingSituationName} " +
             "FROM ClosingSituations;";
 
         /// <summary>
@@ -44,7 +47,7 @@
             $"WindDirections.WindDirectionId = GoverningWind.WindDirectionId as {IllustrationPointsDatabaseConstants.IsGoverning} " +
             "FROM WindDirections " +
             "JOIN GoverningWind " +
-            "WHERE OuterIterationId = (SELECT MAX(OuterIterationID) FROM GoverningWind);";
+            $"WHERE {lastIteration};";
 
         /// <summary>
         /// Selects all the sub mechanisms.
@@ -74,8 +77,8 @@
             "FROM DesignAlpha " +
             "JOIN Stochasts USING(StochastId) " +
             "WHERE LevelTypeId = 4 " +
-            "AND OuterIterationId = (SELECT MAX(OuterIterationId) FROM DesignAlpha) " +
-            "AND PeriodId = (SELECT MIN(PeriodId) FROM DesignAlpha);";
+            $"AND {lastIteration} " +
+            $"AND {firstPeriod};";
 
         /// <summary>
         /// Selects the beta values for a general result.
@@ -84,8 +87,8 @@
             $"SELECT {IllustrationPointsDatabaseConstants.BetaValue} " +
             "FROM DesignBeta " +
             "WHERE LevelTypeId = 4 " +
-            "AND OuterIterationId = (SELECT MAX(OuterIterationId) FROM DesignAlpha) " +
-            "AND PeriodId = (SELECT MIN(PeriodId) FROM DesignAlpha);";
+            $"AND {lastIteration} " +
+            $"AND {firstPeriod};";
 
         /// <summary>
         /// Selects the alpha values for each fault tree illustration point.
@@ -102,8 +105,8 @@
             "JOIN DesignAlpha USING(FaultTreeId) " +
             "JOIN Stochasts USING(StochastId) " +
             "WHERE DesignAlpha.LevelTypeId = 5 " +
-            "AND PeriodId = (SELECT MIN(PeriodId) FROM DesignAlpha) " +
-            "AND OuterIterationId = (SELECT MAX(OuterIterationId) FROM DesignAlpha);";
+            $"AND {lastIteration} " +
+            $"AND {firstPeriod};";
 
         /// <summary>
         /// Selects the beta values for each fault tree illustration point.
@@ -117,8 +120,8 @@
             "FROM FaultTrees " +
             "JOIN DesignBeta USING(FaultTreeId) " +
             "WHERE DesignBeta.LevelTypeId = 5 " +
-            "AND PeriodId = (SELECT MIN(PeriodId) FROM DesignBeta) " +
-            "AND OuterIterationId = (SELECT MAX(OuterIterationId) FROM DesignBeta);";
+            $"AND {lastIteration} " +
+            $"AND {firstPeriod};";
 
         /// <summary>
         /// Selects the alpha values for each sub mechanism illustration point.
@@ -132,12 +135,12 @@
             $"{IllustrationPointsDatabaseConstants.AlphaValue}," +
             $"{IllustrationPointsDatabaseConstants.Duration}, " +
             $"{IllustrationPointsDatabaseConstants.Realization} " +
-            $"FROM SubMechanisms " +
+            "FROM SubMechanisms " +
             "JOIN DesignAlpha USING(SubMechanismId) " +
             "JOIN Stochasts USING(StochastId) " +
             "WHERE DesignAlpha.LevelTypeId = 7 " +
-            "AND PeriodId = (SELECT MIN(PeriodId) FROM DesignAlpha) " +
-            "AND OuterIterationId = (SELECT MAX(OuterIterationId) FROM DesignAlpha);";
+            $"AND {lastIteration} " +
+            $"AND {firstPeriod};";
 
         /// <summary>
         /// Selects the beta values for each sub mechanism illustration point.
@@ -151,8 +154,8 @@
             "FROM SubMechanisms " +
             "JOIN DesignBeta USING(SubMechanismId) " +
             "WHERE DesignBeta.LevelTypeId = 7 " +
-            "AND PeriodId = (SELECT MIN(PeriodId) FROM DesignBeta) " +
-            "AND OuterIterationId = (SELECT MAX(OuterIterationId) FROM DesignBeta);";
+            $"AND {lastIteration} " +
+            $"AND {firstPeriod};";
 
         /// <summary>
         /// Selects the output variables for each sub mechanism illustration point.
@@ -167,8 +170,8 @@
             "FROM SubMechanisms " +
             "JOIN DesignPointResults USING(SubMechanismId) " +
             "JOIN OutputVariables USING(OutputVariableId) " +
-            "WHERE PeriodId = (SELECT MIN(PeriodId) FROM DesignPointResults) " +
-            "AND OuterIterationId = (SELECT MAX(OuterIterationId) FROM DesignPointResults);";
+            $"WHERE {lastIteration} " +
+            $"AND {firstPeriod};";
 
         /// <summary>
         /// Selects all the illustration points from the fault tree.
Index: Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/IllustrationPointsParser.cs
===================================================================
diff -u -r288827a5a3e825d8e47cff85d76495e2601483f1 -r648d6c8d5c952943c3f428981f97c1cdd8b0bd37
--- Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/IllustrationPointsParser.cs	(.../IllustrationPointsParser.cs)	(revision 288827a5a3e825d8e47cff85d76495e2601483f1)
+++ Ringtoets/HydraRing/src/Ringtoets.HydraRing.Calculation/Parsers/IllustrationPoints/IllustrationPointsParser.cs	(.../IllustrationPointsParser.cs)	(revision 648d6c8d5c952943c3f428981f97c1cdd8b0bd37)
@@ -34,6 +34,11 @@
     /// </summary>
     public class IllustrationPointsParser : IHydraRingFileParser
     {
+        /// <summary>
+        /// The result of parsing the illustration points in the Hydra-Ring database.
+        /// </summary>
+        public readonly GeneralResult Output = new GeneralResult();
+
         private readonly Dictionary<ThreeKeyIndex, IList<Stochast>> faultTreeStochasts = new Dictionary<ThreeKeyIndex, IList<Stochast>>();
         private readonly Dictionary<ThreeKeyIndex, double> faultTreeBetaValues = new Dictionary<ThreeKeyIndex, double>();
 
@@ -46,11 +51,6 @@
         private IDictionary<int, string> subMechanisms;
         private IDictionary<int, string> faultTrees;
 
-        /// <summary>
-        /// The result of parsing the illustration points in the Hydra-Ring database.
-        /// </summary>
-        public readonly GeneralResult Output = new GeneralResult();
-
         public void Parse(string workingDirectory, int sectionId)
         {
             string query = string.Concat(
@@ -324,7 +324,7 @@
             {
                 Name = faultTrees[faultTreeId],
                 Beta = faultTreeBetaValues[dataKey],
-                Combine = combinationType
+                CombinationType = combinationType
             };
             if (faultTreeStochasts.ContainsKey(dataKey))
             {
@@ -360,7 +360,7 @@
             return new IllustrationPointTreeNode(illustrationPoint);
         }
 
-        private void AddRange<T>(ICollection<T> collection, IEnumerable<T> itemsToAdd)
+        private static void AddRange<T>(ICollection<T> collection, IEnumerable<T> itemsToAdd)
         {
             foreach (T item in itemsToAdd)
             {
@@ -370,39 +370,36 @@
 
         private void ParseGeneralBetaValue(HydraRingDatabaseReader reader)
         {
-            IEnumerable<Dictionary<string, object>> betaValues = GetIterator(reader).ToArray();
-            if (betaValues.Count() != 1)
+            Dictionary<string, object>[] betaValues = GetIterator(reader).ToArray();
+            if (betaValues.Length != 1)
             {
                 throw new HydraRingFileParserException(Resources.IllustrationPointsParser_Parse_Multiple_values_for_beta_of_illustration_point_found);
             }
-            Output.Beta = Convert.ToDouble(betaValues.First()[IllustrationPointsDatabaseConstants.BetaValue]);
+            Output.Beta = Convert.ToDouble(betaValues[0][IllustrationPointsDatabaseConstants.BetaValue]);
         }
 
         private void ParseGeneralAlphaValues(HydraRingDatabaseReader reader)
         {
-            IEnumerable<Dictionary<string, object>> alphaValues = GetIterator(reader).ToArray();
-            Output.Stochasts = alphaValues.Select(a => new Stochast
+            Output.Stochasts = GetIterator(reader).Select(a => new Stochast
             {
                 Name = Convert.ToString(a[IllustrationPointsDatabaseConstants.StochastName]),
                 Duration = Convert.ToDouble(a[IllustrationPointsDatabaseConstants.Duration]),
                 Alpha = Convert.ToDouble(a[IllustrationPointsDatabaseConstants.AlphaValue])
-            });
+            }).ToArray();
         }
 
         private void ParseClosingSituations(HydraRingDatabaseReader reader)
         {
-            IEnumerable<Dictionary<string, object>> readClosingSituations = GetIterator(reader).ToArray();
-            closingSituations = readClosingSituations.ToDictionary(
+            closingSituations = GetIterator(reader).ToDictionary(
                 r => Convert.ToInt32(r[IllustrationPointsDatabaseConstants.ClosingSituationId]),
                 r => Convert.ToString(r[IllustrationPointsDatabaseConstants.ClosingSituationName]));
         }
 
         private void ParseWindDirections(HydraRingDatabaseReader reader)
         {
-            IEnumerable<Dictionary<string, object>> readWindDirections = GetIterator(reader).ToArray();
             windDirections = new Dictionary<int, WindDirection>();
 
-            foreach (Dictionary<string, object> readWindDirection in readWindDirections)
+            foreach (Dictionary<string, object> readWindDirection in GetIterator(reader))
             {
                 int key = Convert.ToInt32(readWindDirection[IllustrationPointsDatabaseConstants.WindDirectionId]);
                 string name = Convert.ToString(readWindDirection[IllustrationPointsDatabaseConstants.WindDirectionName]);
@@ -425,16 +422,14 @@
 
         private void ParseSubMechanisms(HydraRingDatabaseReader reader)
         {
-            IEnumerable<Dictionary<string, object>> readSubMechanisms = GetIterator(reader).ToArray();
-            subMechanisms = readSubMechanisms.ToDictionary(
+            subMechanisms = GetIterator(reader).ToDictionary(
                 r => Convert.ToInt32(r[IllustrationPointsDatabaseConstants.SubMechanismId]),
                 r => Convert.ToString(r[IllustrationPointsDatabaseConstants.SubMechanismName]));
         }
 
         private void ParseFaultTrees(HydraRingDatabaseReader reader)
         {
-            IEnumerable<Dictionary<string, object>> readFaultTrees = GetIterator(reader).ToArray();
-            faultTrees = readFaultTrees.ToDictionary(
+            faultTrees = GetIterator(reader).ToDictionary(
                 r => Convert.ToInt32(r[IllustrationPointsDatabaseConstants.FaultTreeId]),
                 r => Convert.ToString(r[IllustrationPointsDatabaseConstants.FaultTreeName]));
         }
Index: Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Parsers/IllustrationPoints/FaultTreeIllustrationPointTest.cs
===================================================================
diff -u -r6d67c42595915b7385a6cf2f13885abc9ed1fad0 -r648d6c8d5c952943c3f428981f97c1cdd8b0bd37
--- Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Parsers/IllustrationPoints/FaultTreeIllustrationPointTest.cs	(.../FaultTreeIllustrationPointTest.cs)	(revision 6d67c42595915b7385a6cf2f13885abc9ed1fad0)
+++ Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Parsers/IllustrationPoints/FaultTreeIllustrationPointTest.cs	(.../FaultTreeIllustrationPointTest.cs)	(revision 648d6c8d5c952943c3f428981f97c1cdd8b0bd37)
@@ -37,7 +37,7 @@
             Assert.IsInstanceOf<IIllustrationPoint>(illustrationPoint);
             Assert.IsEmpty(illustrationPoint.Stochasts);
             Assert.IsNaN(illustrationPoint.Beta);
-            Assert.AreEqual(CombinationType.Or, illustrationPoint.Combine);
+            Assert.AreEqual(CombinationType.Or, illustrationPoint.CombinationType);
         }
     }
 }
\ No newline at end of file
Index: Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Parsers/IllustrationPoints/IllustrationPointResultTest.cs
===================================================================
diff -u -r6d67c42595915b7385a6cf2f13885abc9ed1fad0 -r648d6c8d5c952943c3f428981f97c1cdd8b0bd37
--- Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Parsers/IllustrationPoints/IllustrationPointResultTest.cs	(.../IllustrationPointResultTest.cs)	(revision 6d67c42595915b7385a6cf2f13885abc9ed1fad0)
+++ Ringtoets/HydraRing/test/Ringtoets.HydraRing.Calculation.Test/Parsers/IllustrationPoints/IllustrationPointResultTest.cs	(.../IllustrationPointResultTest.cs)	(revision 648d6c8d5c952943c3f428981f97c1cdd8b0bd37)
@@ -27,7 +27,6 @@
     [TestFixture]
     public class IllustrationPointResultTest
     {
-
         [Test]
         public void Constructor_Always_ReturnsNewInstance()
         {