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FromTableReordering.h File Reference
#include "InputMetadata.h"
#include "RelAlgExecutionUnit.h"
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Functions

std::vector< size_t > get_node_input_permutation (const JoinQualsPerNestingLevel &left_deep_join_quals, const std::vector< InputTableInfo > &table_infos, const Executor *executor)
 

Function Documentation

std::vector<size_t> get_node_input_permutation ( const JoinQualsPerNestingLevel left_deep_join_quals,
const std::vector< InputTableInfo > &  table_infos,
const Executor executor 
)

Definition at line 572 of file FromTableReordering.cpp.

References anonymous_namespace{FromTableReordering.cpp}::build_join_cost_graph(), and anonymous_namespace{FromTableReordering.cpp}::traverse_join_cost_graph().

Referenced by anonymous_namespace{RelAlgExecutor.cpp}::do_table_reordering().

575  {
576  std::vector<std::map<node_t, InnerQualDecision>> qual_normalization_res(
577  table_infos.size());
578  const auto join_cost_graph = build_join_cost_graph(
579  left_deep_join_quals, table_infos, executor, qual_normalization_res);
580  // Use the number of tuples in each table to break ties in BFS.
581  const auto compare_node = [&table_infos](const node_t lhs_nest_level,
582  const node_t rhs_nest_level) {
583  return table_infos[lhs_nest_level].info.getNumTuplesUpperBound() <
584  table_infos[rhs_nest_level].info.getNumTuplesUpperBound();
585  };
586  const auto compare_edge = [&compare_node](const TraversalEdge& lhs_edge,
587  const TraversalEdge& rhs_edge) {
588  // Only use the number of tuples as a tie-breaker, if costs are equal.
589  if (lhs_edge.join_cost == rhs_edge.join_cost) {
590  return compare_node(lhs_edge.nest_level, rhs_edge.nest_level);
591  }
592  return lhs_edge.join_cost > rhs_edge.join_cost;
593  };
594  return traverse_join_cost_graph(join_cost_graph,
595  table_infos,
596  compare_node,
597  compare_edge,
598  left_deep_join_quals,
599  qual_normalization_res);
600 }
std::vector< std::map< node_t, cost_t > > build_join_cost_graph(const JoinQualsPerNestingLevel &left_deep_join_quals, const std::vector< InputTableInfo > &table_infos, const Executor *executor, std::vector< std::map< node_t, InnerQualDecision >> &qual_detection_res)
std::vector< node_t > traverse_join_cost_graph(const std::vector< std::map< node_t, cost_t >> &join_cost_graph, const std::vector< InputTableInfo > &table_infos, const std::function< bool(const node_t lhs_nest_level, const node_t rhs_nest_level)> &compare_node, const std::function< bool(const TraversalEdge &, const TraversalEdge &)> &compare_edge, const JoinQualsPerNestingLevel &left_deep_join_quals, std::vector< std::map< node_t, InnerQualDecision >> &qual_normalization_res)

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