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EITS member variables in both TABLE and TABLE_SHARE?

To: igor@xxxxxxxxxxx, igor@xxxxxxxxxxxx
From: Sergey Petrunia <sergey@xxxxxxxxxxx>
Date: Sat, 30 Mar 2019 00:02:03 +0300
Cc: maria-developers@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.9.4 (2018-02-28)

Hello Igor,

TABLE_SHARE has TABLE_STATISTICS_CB, which has these members:
struct TABLE_STATISTICS_CB
{
  ...
  bool stats_is_read;            /* Statistical data for table has been read
                                    from statistical tables */
  bool histograms_are_read;
}

At the same time, TABLE has:

struct TABLE
{
  ...
  bool stats_is_read;     /* Persistent statistics is read for the table */
  bool histograms_are_read;

I would like to understand why both structures need these variables? Is there
any difference in meaning between them?

BR
 Sergei
-- 
Sergei Petrunia, Software Developer
MariaDB Corporation | Skype: sergefp | Blog: http://s.petrunia.net/blog