Re: Performance problem with outer join

[Rick James]

> | 1 | SIMPLE | datausage | ALL | NULL | NULL | NULL | NULL | 96805 | Using where; Using join buffer (Block Nested Loop) |

Note "ALL" and "NULL". That is saying it is not even using the index to do the JOIN. Here's why:

`accountID` varchar(25) COLLATE utf8_unicode_ci NOT NULL ... DEFAULT CHARSET=utf8
`AccountID` varchar(25) ... DEFAULT CHARSET=latin1 ;

Inconsistent CHARSETs make it 'impossible' to use the index. Hence it has to scan Datausage again and again.

Make the schema consistent.