SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 2) Identifier value Identifier changed TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier system.settings Function equals (children 1) ExpressionList (children 2) Identifier name Literal \'compatibility\'