SQL Layer should pass innodb page numbers for range scan

check_quick_select()

{

   // We're considering range access on some index

   ha_innobase::multi_range_info_const()

   { 

     dsmrr_info_const()

     {

       for each range {

         // this returns page rage for this interval.

         ha_innobase::record_in_range(&page_range);

         // build one single page range that covers

         // all intervals we'll scan.

       }

       // return the page range.

     }

     // return page range.

   }

   // Save the page range (denote $PR) that covers all intervals.

   // We'll use it in the range.

}

QUICK_RANGE_SELECT::reset()

{

  // Provide saved $PR to the storage engine.

  file->advise_page_range(&mrr_pages_range);

  file->multi_range_read_init(...);

}

class ha_innobase {

...

  page_range m_scanned_page_range;

  // inform the storage engine that we're going to read pages in this range.

  // UNUSED_PAGE_NO means "no information".

  void advise_page_range(page_range *);

  int reset() override {

    m_scanned_page_range = { UNUSED_PAGE_NO, UNUSED_PAGE_NO};

  }

}

create table t2 (a int, b int, index(a), index(b));

insert into t2 select seq, seq from seq_1_to_10000;

analyze

select * from t2 where a in (10, 1000, 2000) and b between 200 and 300;

records_in_range(

  index=a

  page_range={42949672969, 42949672969}

)

records_in_range(

  index=a

  page_range={42949672970, 42949672970}

)

records_in_range(

  index=a

  page_range={42949672974, 42949672974}

)

range estimation(index=a):

  page_range={42949672969, 42949672974}

)

records_in_range(

  index=b

  page_range={42949672971, 42949672971}

)

range estimation(index=b):

  page_range={42949672971, 42949672971}

)

ha_innobase::multi_range_read_init(

  active_index=a

  m_scanned_page_range={42949672969, 42949672974}

)