rowid_ordered_retrieval_plan.h

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#ifndef SQL_RANGE_OPTIMIZER_ROWID_ORDERED_RETRIEVAL_PLAN_H_
#define SQL_RANGE_OPTIMIZER_ROWID_ORDERED_RETRIEVAL_PLAN_H_
 
#include <sys/types.h>
 
#include "my_base.h"
#include "sql/handler.h"
#include "sql/join_optimizer/overflow_bitset.h"
#include "sql/range_optimizer/range_opt_param.h"
#include "sql/range_optimizer/range_optimizer.h"
 
class Opt_trace_object;
class RANGE_OPT_PARAM;
class SEL_ROOT;
class SEL_TREE;
struct MEM_ROOT;
 
// TODO(sgunders): Consider whether we can create INDEX_RANGE_SCAN AccessPaths
// directly, instead of first creating this structure and then creating
// AccessPaths from it.
struct ROR_SCAN_INFO {
  uint idx;         ///< # of used key in param->keys
  uint keynr;       ///< # of used key in table
  ha_rows records;  ///< estimate of # records this scan will return
 
  /** Set of intervals over key fields that will be used for row retrieval. */
  SEL_ROOT *sel_root;
 
  /** Fields used in the query and covered by this ROR scan. */
  OverflowBitset covered_fields;
 
  /**
    Cost of reading all index records with values in sel_arg intervals set
    (assuming there is no need to access full table records)
  */
  Cost_estimate index_read_cost;
 
  /**
    The ranges to scan for this index. Must be allocated on the return_mem_root.
   */
  Bounds_checked_array<QUICK_RANGE *> ranges;
  uint used_key_parts;
};
 
// Planning related information when picking the best combination
// of rowid ordered scans for a ROR-Intersect plan.
class ROR_intersect_plan {
 public:
  ROR_intersect_plan(const RANGE_OPT_PARAM *param, size_t num_fields);
  ROR_intersect_plan(const ROR_intersect_plan &) = delete;
  ROR_intersect_plan &operator=(const ROR_intersect_plan &plan);
 
  bool add(OverflowBitset needed_fields, ROR_SCAN_INFO *ror_scan,
           bool is_cpk_scan, Opt_trace_object *trace_costs, bool ignore_cost);
  double get_scan_selectivity(const ROR_SCAN_INFO *scan) const;
  size_t num_scans() const { return m_ror_scans.size(); }
 
 public:
  /// Range optimizer parameter
  const RANGE_OPT_PARAM *m_param;
  /// Rowid ordered scans that are part of this plan.
  Mem_root_array<ROR_SCAN_INFO *> m_ror_scans;
  /// Whether this plan with the chosen rowid ordered scans is covering or not.
  bool m_is_covering{false};
  /// Output rows for this plan.
  double m_out_rows;
  /// Total cost for the plan - m_index_read_cost + disk_sweep_cost
  Cost_estimate m_total_cost;
 
 private:
  /// Bitmap of fields covered by the scans in the plan.
  OverflowBitset m_covered_fields;
  /// Number of rows to be read from indexes that are used for rowid ordered
  /// scans
  ha_rows m_index_records{0};
  /// Total cost for reading the indexes picked in the plan.
  Cost_estimate m_index_read_cost;
};
 
AccessPath *get_best_ror_intersect(THD *thd, const RANGE_OPT_PARAM *param,
                                   TABLE *table,
                                   bool index_merge_intersect_allowed,
                                   SEL_TREE *tree, double cost_est,
                                   bool force_index_merge_result,
                                   bool reuse_handler);
 
void trace_basic_info_rowid_intersection(THD *thd, const AccessPath *path,
                                         const RANGE_OPT_PARAM *param,
                                         Opt_trace_object *trace_object);
 
void trace_basic_info_rowid_union(THD *thd, const AccessPath *path,
                                  const RANGE_OPT_PARAM *param,
                                  Opt_trace_object *trace_object);
 
void add_keys_and_lengths_rowid_intersection(const AccessPath *path,
                                             String *key_names,
                                             String *used_lengths);
 
void add_keys_and_lengths_rowid_union(const AccessPath *path, String *key_names,
                                      String *used_lengths);
 
OverflowBitset get_needed_fields(const RANGE_OPT_PARAM *param);
 
ROR_SCAN_INFO *make_ror_scan(const RANGE_OPT_PARAM *param, int idx,
                             SEL_ROOT *sel_root, OverflowBitset needed_fields);
 
void find_intersect_order(Mem_root_array<ROR_SCAN_INFO *> *ror_scans,
                          OverflowBitset needed_fields, MEM_ROOT *mem_root);
 
AccessPath *MakeRowIdOrderedIndexScanAccessPath(ROR_SCAN_INFO *scan,
                                                TABLE *table,
                                                KEY_PART *used_key_part,
                                                bool reuse_handler,
                                                MEM_ROOT *mem_root);
 
#ifndef NDEBUG
void dbug_dump_rowid_intersection(int indent, bool verbose,
                                  const Mem_root_array<AccessPath *> &children);
 
void dbug_dump_rowid_union(int indent, bool verbose,
                           const Mem_root_array<AccessPath *> &children);
#endif
 
#endif  // SQL_RANGE_OPTIMIZER_ROWID_ORDERED_RETRIEVAL_PLAN_H_