+----------------------+ | @@debug | +----------------------+ | d,error,warning,loop | +----------------------+ mysql> SET debug = ’-d,error,loop’; mysql> SELECT @@debug; +-----------+ | @@debug | +-----------+ | d,warning | +-----------+ 

Adding to “all macros enabled”  results in no change: 

mysql> SET debug = ’d’; mysql> SELECT @@debug; +---------+ | @@debug | +---------+ | d | +---------+ mysql> SET debug = ’+d,loop’; mysql> SELECT @@debug; +---------+ | @@debug | +---------+ | d | +---------+ 

Disabling all enabled macros disables the d  flag entirely: 

mysql> SET debug = ’d,error,loop’; mysql> SELECT @@debug; +--------------+ | @@debug | +--------------+ | d,error,loop | +--------------+ mysql> SET debug = ’-d,error,loop’; mysql> SELECT @@debug; +---------+ | @@debug | +---------+ | | +---------+ 

