The unsung heroes of InnoDB are the logfiles. They are what makes InnoDB automatic crash recovery possible.Database administrators of other DBMS may be familiar with the concept of a "redo" log. When data is changed, affected data pages are changed in the innodb_buffer_pool. Then, the change is written to the redo log, which in MySQL is the InnoDB logfile (ib_logfile0 and ib_logfile1). The pages are marked as "dirty", and eventually get flushed and written to disk.If MySQL crashes, t

Do you "have_community_features"? I do!SHOW GLOBAL VARIABLES LIKE 'have_community_features';+-------------------------+-------+| Variable_name | Value |+-------------------------+-------+| have_community_features | YES | +-------------------------+-------+1 row in set (0.00 sec)I am pretty sure this is one of those variables that MySQL has put in as an unused placeholder, but for now, it is not even documented as unused (as are table_lock_wait_timeout,

Today's contradiction:MySQL has server variables named "new" and "old".The "new" variable can be set per-session and globally, and is dynamic. The "old" variable is not dynamic, and only global in scope. Both default to FALSE in MySQL 5.1.According to the manual, the "new" variable:was used in MySQL 4.0 to turn on some 4.1