Package com.espertech.esper.common.internal.epl.join.queryplanbuild

Class NStreamQueryPlanBuilder

java.lang.Object
com.espertech.esper.common.internal.epl.join.queryplanbuild.NStreamQueryPlanBuilder
public class NStreamQueryPlanBuilder extends Object
Builds a query plan for 3 or more streams in a join.

  • Constructor Details

    • NStreamQueryPlanBuilder

      public NStreamQueryPlanBuilder()

  • Method Details

    • build

      protected static QueryPlanForgeDesc build(QueryGraphForge queryGraph, EventType[] typesPerStream, HistoricalViewableDesc historicalViewableDesc, DependencyGraph dependencyGraph, HistoricalStreamIndexListForge[] historicalStreamIndexLists, boolean hasForceNestedIter, String[][][] indexedStreamsUniqueProps, TableMetaData[] tablesPerStream, StreamJoinAnalysisResultCompileTime streamJoinAnalysisResult, StatementRawInfo raw, SerdeCompileTimeResolver serdeResolver)

    • createStreamPlan

      protected static QueryPlanNodeForgeDesc createStreamPlan(int lookupStream, int[] bestChain, QueryGraphForge queryGraph, QueryPlanIndexForge[] indexSpecsPerStream, EventType[] typesPerStream, boolean[] isHistorical, HistoricalStreamIndexListForge[] historicalStreamIndexLists, TableMetaData[] tablesPerStream, StreamJoinAnalysisResultCompileTime streamJoinAnalysisResult, StatementRawInfo raw, SerdeCompileTimeResolver serdeResolver)
      Walks the chain of lookups and constructs lookup strategy and plan specification based on the index specifications.
      Parameters:
      lookupStream - - the stream to construct the query plan for
      bestChain - - the chain that the lookup follows to make best use of indexes
      queryGraph - - the repository for key properties to indexes
      indexSpecsPerStream - - specifications of indexes
      typesPerStream - - event types for each stream
      isHistorical - - indicator for each stream if it is a historical streams or not
      historicalStreamIndexLists - - index management, populated for the query plan
      tablesPerStream - tables
      streamJoinAnalysisResult - stream join analysis
      raw - raw info
      serdeResolver - serde resolver
      Returns:
      NestedIterationNode with lookups attached underneath

    • createLookupPlan

      public static TableLookupPlanDesc createLookupPlan(QueryGraphForge queryGraph, int currentLookupStream, int indexedStream, boolean indexedStreamIsVDW, QueryPlanIndexForge indexSpecs, EventType[] typesPerStream, TableMetaData indexedStreamTableMeta, StatementRawInfo raw, SerdeCompileTimeResolver serdeResolver)
      Create the table lookup plan for a from-stream to look up in an indexed stream using the columns supplied in the query graph and looking at the actual indexes available and their index number.
      Parameters:
      queryGraph - - contains properties joining the 2 streams
      currentLookupStream - - stream to use key values from
      indexedStream - - stream to look up in
      indexSpecs - - index specification defining indexes to be created for stream
      typesPerStream - - event types for each stream
      indexedStreamTableMeta - table info
      indexedStreamIsVDW - vdw indicators
      raw - raw info
      serdeResolver - serde resolver
      Returns:
      plan for performing a lookup in a given table using one of the indexes supplied

    • computeBestPath

      protected static NStreamQueryPlanBuilder.BestChainResult computeBestPath(int lookupStream, QueryGraphForge queryGraph, DependencyGraph dependencyGraph)
      Compute a best chain or path for lookups to take for the lookup stream passed in and the query property relationships. The method runs through all possible permutations of lookup path NumberSetPermutationEnumeration until a path is found in which all streams can be accessed via an index. If not such path is found, the method returns the path with the greatest depth, ie. where the first one or more streams are index accesses. If no depth other then zero is found, returns the default nesting order.
      Parameters:
      lookupStream - - stream to start look up
      queryGraph - - navigability between streams
      dependencyGraph - - dependencies between historical streams
      Returns:
      chain and chain depth

    • isDependencySatisfied

      protected static boolean isDependencySatisfied(int lookupStream, int[] permutation, DependencyGraph dependencyGraph)
      Determine if the proposed permutation of lookups passes dependencies
      Parameters:
      lookupStream - stream to initiate
      permutation - permutation of lookups
      dependencyGraph - dependencies
      Returns:
      pass or fail indication

    • computeNavigableDepth

      protected static int computeNavigableDepth(int lookupStream, int[] nextStreams, QueryGraphForge queryGraph)
      Given a chain of streams to look up and indexing information, compute the index within the chain of the first non-index lookup.
      Parameters:
      lookupStream - - stream to start lookup for
      nextStreams - - list of stream numbers next in lookup
      queryGraph - - indexing information
      Returns:
      value between 0 and (nextStreams.lenght - 1)

    • buildDefaultNestingOrder

      protected static int[] buildDefaultNestingOrder(int numStreams, int forStream)
      Returns default nesting order for a given number of streams for a certain stream. Example: numStreams = 5, forStream = 2, result = {0, 1, 3, 4} The resulting array has all streams except the forStream, in ascdending order.
      Parameters:
      numStreams - - number of streams
      forStream - - stream to generate a nesting order for
      Returns:
      int array with all stream numbers starting at 0 to (numStreams - 1) leaving the forStream out