protected override void OnExecute()
{
using (var scope = new DatabaseScope(context.Database.Name))
{
virtualIndicesRepository.DestroyAll();
foreach (var index in context.IndicesDesignData.PossibleIndices.All)
{
Dictionary <AttributeData, List <string> > possibleFilteredAttributeValues = new Dictionary <AttributeData, List <string> >();
foreach (var a in index.Attributes)
{
List <string> mostSignificantValues = new List <string>();
List <string> leastSignificantValues = new List <string>();
if (a.MostCommonValuesFrequencies != null && a.MostCommonValuesFrequencies.Length >= 2)// we need at least two values
{
decimal frequenciesSum = 0;
for (int i = 0; i < Math.Min(a.MostCommonValuesFrequencies.Length - 1, MOST_COMMON_VALUES_MAX_COUNT); i++)
{
if (a.MostCommonValuesFrequencies[i] >= MOST_COMMON_VALUE_MIN_FREQUENCY)
{
var sqlStringValue = toSqlValueStringConverter.ConvertStringRepresentation(a.DbType, a.MostCommonValues[i]);
if (sqlStringValue != null)
{
mostSignificantValues.Add(sqlStringValue);
frequenciesSum += a.MostCommonValuesFrequencies[i];
}
}
}
if (frequenciesSum < MOST_COMMON_VALUES_MIN_FREQUENCIES_SUM || frequenciesSum > MOST_COMMON_VALUES_MAX_FREQUENCIES_SUM)
{
mostSignificantValues.Clear();
}
frequenciesSum = 0;
for (int i = a.MostCommonValuesFrequencies.Length - 1; i >= Math.Max(1, a.MostCommonValuesFrequencies.Length - MOST_COMMON_VALUES_MAX_COUNT + 1); i--)
{
var sqlStringValue = toSqlValueStringConverter.ConvertStringRepresentation(a.DbType, a.MostCommonValues[i]);
if (sqlStringValue != null)
{
leastSignificantValues.Add(sqlStringValue);
frequenciesSum += a.MostCommonValuesFrequencies[i];
}
}
if (frequenciesSum > MOST_COMMON_VALUES_MIN_FREQUENCIES_SUM)
{
leastSignificantValues.Clear();
}
}
if (mostSignificantValues.Count > 0)
{
possibleFilteredAttributeValues.Add(a, mostSignificantValues);
}
else if (leastSignificantValues.Count > 0)
{
possibleFilteredAttributeValues.Add(a, leastSignificantValues);
}
}
if (possibleFilteredAttributeValues.Count > 0)
{
string filter = CreateFilterString(possibleFilteredAttributeValues);
var targetRelationData = context.RelationsData.GetReplacementOrOriginal(index.Relation.ID);
var virtualIndex = virtualIndicesRepository.Create(dbObjectDefinitionGenerator.Generate(index.WithReplacedRelation(targetRelationData), filter));
var size = virtualIndicesRepository.GetVirtualIndexSize(virtualIndex.ID);
var filters = new Dictionary <string, long>();
filters.Add(filter, size);
context.IndicesDesignData.PossibleIndexFilters.Add(index, filters);
}
}
}
}
protected override void OnExecute()
{
context.IndicesDesignData.PossibleIndexSizes.Clear();
#if DEBUG
int counter = 0;
#endif
using (var scope = new DatabaseScope(context.Database.Name))
{
foreach (var env in context.IndicesDesignData.Environments)
{
#if DEBUG
if (System.Diagnostics.Debugger.IsAttached)
{
++counter;
if (counter % 10 == 0)
{
Console.WriteLine(((counter / (double)context.IndicesDesignData.Environments.Count) * 100).ToString("F2") + "%");
}
}
#endif
try
{
virtualIndicesRepository.DestroyAll();
var virtualIndicesMapping = new Dictionary <IndexDefinition, IVirtualIndex>();
bool indicesCreated = false;
try
{
foreach (var index in env.PossibleIndices.All)
{
var targetRelationData = context.RelationsData.GetReplacementOrOriginal(index.Relation.ID);
var virtualIndex = virtualIndicesRepository.Create(dbObjectDefinitionGenerator.Generate(index.WithReplacedRelation(targetRelationData)));
if (virtualIndex != null)
{
virtualIndicesMapping.Add(index, virtualIndex);
}
if (!context.IndicesDesignData.PossibleIndexSizes.ContainsKey(index))
{
context.IndicesDesignData.PossibleIndexSizes.Add(index, virtualIndicesRepository.GetVirtualIndexSize(virtualIndex.ID));
}
}
indicesCreated = true;
}
catch (Exception ex)
{
log.Write(ex);
}
if (indicesCreated)
{
foreach (var kv in env.PossibleIndices.AllPerStatement)
{
var statementID = kv.Key;
var indices = kv.Value;
var workloadStatement = context.StatementsData.All[statementID];
var normalizedStatement = workloadStatement.NormalizedStatement;
var representativeStatement = workloadStatement.RepresentativeStatistics.RepresentativeStatement;
var statementToUse = RepresentativeStatementReplacementUtility.Provide(normalizedStatement, representativeStatement, context.RelationsData);
var explainResult = explainRepository.Eplain(statementToUse);
var latestPlan = explainResult.Plan;
var realPlan = context.RealExecutionPlansForStatements[statementID].Plan;
HashSet <IndexDefinition> improvingVirtualIndices = new HashSet <IndexDefinition>();
VirtualEnvironmentStatementEvaluation statementEvaluation = new VirtualEnvironmentStatementEvaluation();
statementEvaluation.ExecutionPlan = explainResult;
decimal fromPrice = realPlan.TotalCost;
decimal toPrice = latestPlan.TotalCost;
decimal divisor = Math.Abs(Math.Max(fromPrice, toPrice));
if (divisor > 0)
{
statementEvaluation.LocalImprovementRatio = ((toPrice - fromPrice) / divisor) * -1m;
}
decimal statementPortion = context.StatementsData.AllExecutionsCount > 0 ? workloadStatement.TotalExecutionsCount / (decimal)context.StatementsData.AllExecutionsCount : 0m;
statementEvaluation.GlobalImprovementRatio = statementEvaluation.LocalImprovementRatio * statementPortion;
env.StatementsEvaluation.Add(statementID, statementEvaluation);
foreach (var i in indices)
{
var virtualIndex = virtualIndicesMapping[i];
if (!env.IndicesEvaluation.ContainsKey(i))
{
env.IndicesEvaluation.Add(i, new VirtualIndicesEnvironmentIndexEvaluation());
}
if (explainResult.UsedIndexScanIndices.Contains(virtualIndex.Name))
{
statementEvaluation.UsedIndices.Add(i);
statementEvaluation.AffectingIndices.Add(i);
if (latestPlan.TotalCost < realPlan.TotalCost)
{
improvingVirtualIndices.Add(i);
}
env.IndicesEvaluation[i].ImprovementRatio += statementEvaluation.GlobalImprovementRatio;
}
else
{
if (normalizedStatement.CommandType == DAL.Contracts.StatementQueryCommandType.Insert ||
normalizedStatement.CommandType == DAL.Contracts.StatementQueryCommandType.Update ||
normalizedStatement.CommandType == DAL.Contracts.StatementQueryCommandType.Delete)
{
statementEvaluation.AffectingIndices.Add(i);
}
}
}
foreach (var query in normalizedStatement.StatementDefinition.IndependentQueries)
{
var queryKey = new NormalizedStatementQueryPair(statementID, query);
env.ImprovingPossibleIndices.TryAddPossibleIndices(improvingVirtualIndices, normalizedStatement, query);
if (env.PossibleIndices.AllCoveringPerQuery.ContainsKey(queryKey))
{
env.ImprovingPossibleIndices.TryAddPossibleCoveringIndices(env.PossibleIndices.AllCoveringPerQuery[queryKey].Intersect(improvingVirtualIndices), normalizedStatement, query);
}
}
}
}
}
finally
{
virtualIndicesRepository.DestroyAll();
}
}
}
}