node_map.h

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#ifndef SQL_JOIN_OPTIMIZER_NODE_MAP_H
#define SQL_JOIN_OPTIMIZER_NODE_MAP_H 1
 
#include <stdint.h>
 
namespace hypergraph {
 
/**
  Since our graphs can never have more than 61 tables, node sets and edge lists
  are implemented using 64-bit bit sets. This allows for a compact
  representation and very fast set manipulation; the algorithm does a fair
  amount of intersections and unions. If we should need extensions to larger
  graphs later (this will require additional heuristics for reducing the search
  space), we can use dynamic bit sets, although at a performance cost (we'd
  probably templatize off the NodeMap type).
 */
using NodeMap = uint64_t;
 
}  // namespace hypergraph
 
#endif  // SQL_JOIN_OPTIMIZER_NODE_MAP_H