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question about translating: someone explain how/ where overhead is used? i cannot produce it.

It's used in the "Space usage" part of the table properties and print view. I guess it only exists for certain table types though; I don't seem to be able to make it show either, and I can't tell where it would come from by looking at the code.

follow the simple set of instructions below to make it show up (and go away again)

# use the test database, create a table, and put some data in USE test; CREATE TABLE a ( a varchar(255) default NULL ) TYPE=MyISAM; INSERT INTO `a` (`a`) VALUES ('fooooooofooooooofooooooo'); INSERT INTO `a` (`a`) VALUES ('fooooooofoooooooWHAM'); INSERT INTO `a` (`a`) VALUES ('fooooooofoooooooBAR'); # now look at the properties of the table, no overhead yet DELETE FROM a WHERE a='fooooooofoooooooWHAM'; # now look at the properties of the table again, there is an overhead now OPTIMIZE TABLE a; # now look at the properties of the table yet again, overhead gone