Commit f8aadb60 authored by unknown's avatar unknown
Browse files

BUG#12542: Added comments 


sql/log_event.cc:
  Added comments
sql/sql_parse.cc:
  Added comments
parent 20108d6f

sql/log_event.cc

+20 −0
Original line number Diff line number Diff line
@@ -1008,6 +1008,16 @@ int Query_log_event::exec_event(struct st_relay_log_info* rli) 
#endif

  clear_all_errors(thd, rli);



  /*

    Note:   We do not need to execute reset_one_shot_variables() if this

            db_ok() test fails.

    Reason: The db stored in binlog events is the same for SET and for

            its companion query.  If the SET is ignored because of

            db_ok(), the companion query will also be ignored, and if

            the companion query is ignored in the db_ok() test of

            ::exec_event(), then the companion SET also have so we

            don't need to reset_one_shot_variables().

  */

  if (db_ok(thd->db, replicate_do_db, replicate_ignore_db))

  {

    thd->set_time((time_t)when);
@@ -1762,6 +1772,16 @@ int Load_log_event::exec_event(NET* net, struct st_relay_log_info* rli, 
    Create_file_log_event::exec_event() and then discarding Append_block and

    al. Another way is do the filtering in the I/O thread (more efficient: no

    disk writes at all).





    Note:   We do not need to execute reset_one_shot_variables() if this

            db_ok() test fails.

    Reason: The db stored in binlog events is the same for SET and for

            its companion query.  If the SET is ignored because of

            db_ok(), the companion query will also be ignored, and if

            the companion query is ignored in the db_ok() test of

            ::exec_event(), then the companion SET also have so we

            don't need to reset_one_shot_variables().

  */

  if (db_ok(thd->db, replicate_do_db, replicate_ignore_db))

  {

sql/sql_parse.cc

+2 −1
Original line number Diff line number Diff line
@@ -1998,7 +1998,8 @@ mysql_execute_command(THD *thd) 


      Exceptions are:

      - SET: we always execute it (Not that many SET commands exists in

        the binary log anyway)

        the binary log anyway -- only 4.1 masters write SET statements,

	in 5.0 there are no SET statements in the binary log)

      - DROP TEMPORARY TABLE IF EXISTS: we always execute it (otherwise we

        have stale files on slave caused by exclusion of one tmp table).

    */