Currently, if a feature class has a definition query (feature class A), and is joined to another feature class (feature class B), only the matching records are displayed in the attribute table for the target feature class after the join (feature class B). This behavior happens even if the "keep all records" option is selected when the join is created. This is described as "expected behavior" in knowledge base article 17725, however, it makes tracking holes in the data much harder without extra steps. It would be nice if the definition query on a feature class was inserted in the join logic to return all records in the original feature class (feature class B). The current work around is to write a query in MS Access (that replaces the definition query in the feature class), then use an ODBC connection to make the resulting table from the Access query available in ArcMap.