SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 3) ExpressionList (children 1) Function equals (children 1) ExpressionList (children 2) Literal UInt64_0 Function position (children 1) ExpressionList (children 2) Literal \'abc\' Function materialize (children 1) ExpressionList (children 1) Literal \'defgh\' TablesInSelectQuery (children 1) TablesInSelectQueryElement (children 1) TableExpression (children 1) TableIdentifier system.numbers Literal UInt64_10