TheBLACKHOLE
storage engine accepts data but discards it and does not store it. When performing binary logging, all inserts to such tables are always logged, regardless of the logging format in use. Updates and deletes are handled differently depending on whether statement based or row based logging is in use. With the statement based logging format, all statements affectingBLACKHOLE
tables are logged, but their effects ignored. When using row-based logging, updates and deletes to such tables are simply skipped—they are not written to the binary log. A warning is logged whenever this occurs.
For this reason we recommend when you replicate to tables using theBLACKHOLE
storage engine that you have thebinlog_format
server variable set toSTATEMENT
, and not to eitherROW
orMIXED
.