Commit 1180c22a authored by davi@moksha.local's avatar davi@moksha.local
Browse files

Bug#28587 SELECT is blocked by INSERT waiting on read lock, even with low_priority_updates 

The problem is that a SELECT on one thread is blocked by INSERT ... ON
DUPLICATE KEY UPDATE on another thread even when low_priority_updates is
activated.

The solution is to possibly downgrade the lock type to the setting of
low_priority_updates if the INSERT cannot be concurrent.
parent f51c6acc

sql/sql_insert.cc

+1 −1
Original line number Diff line number Diff line
@@ -417,7 +417,7 @@ void upgrade_lock_type(THD *thd, thr_lock_type *lock_type, 
  if (duplic == DUP_UPDATE ||

      duplic == DUP_REPLACE && *lock_type == TL_WRITE_CONCURRENT_INSERT)

  {

    *lock_type= TL_WRITE;

    *lock_type= TL_WRITE_DEFAULT;

    return;

  }