range_opt_param.h

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#ifndef SQL_RANGE_OPTIMIZER_RANGE_OPT_PARAM_H_
#define SQL_RANGE_OPTIMIZER_RANGE_OPT_PARAM_H_
 
#include "sql/range_optimizer/internal.h"
 
class RANGE_OPT_PARAM {
 public:
  TABLE *table;             /* Table being analyzed */
  Query_block *query_block; /* Query block the table is part of */
 
  /* Array of parts of all keys for which range analysis is performed */
  KEY_PART *key_parts;
  KEY_PART *key_parts_end;
  // Memory used for allocating AccessPaths and similar
  // objects that are required for a later call to make_quick(), as well as
  // RowIterator objects and allocations they need to do themselves.
  // Typically points to thd->mem_root, but DynamicRangeIterator uses its
  // own MEM_ROOT here, as it needs to delete all the old data and allocate
  // new objects. Note that not all data allocated here will indeed be used;
  // e.g., we may allocate five AccessPaths here but only choose to use one
  // of them.
  MEM_ROOT *return_mem_root;
  // Memory that will be freed when range analysis completes.
  // In particular, this contains the tree built up to analyze
  // the input expressions (SEL_TREE), but not the actual scan ranges
  // decided on and given to the AccessPath (Quick_range).
  MEM_ROOT *temp_mem_root;
  /*
    Number of indexes used in range analysis (In SEL_TREE::keys only first
    #keys elements are not empty)
  */
  uint keys;
 
  /*
    If true, the index descriptions describe real indexes (and it is ok to
    call field->optimize_range(real_keynr[...], ...).
    Otherwise index description describes fake indexes, like a partitioning
    expression.
  */
  bool using_real_indexes;
 
  /*
    used_key_no -> table_key_no translation table. Only makes sense if
    using_real_indexes==true
  */
  uint *real_keynr = nullptr;
 
  /**
    Whether index statistics or index dives should be used when
    estimating the number of rows in an equality range. If true, index
    statistics is used for these indexes.
  */
  bool use_index_statistics;
 
  /// Error handler for this param.
 
  Range_optimizer_error_handler error_handler;
 
  bool has_errors() const { return (error_handler.has_errors()); }
 
  KEY_PART **key = nullptr; /* First key parts of keys used in the query */
};
 
#endif  // SQL_RANGE_OPTIMIZER_RANGE_OPT_PARAM_H_