Relational Representation of Cross-tabs item-name color number Cross-tabs can be represented skirt dark 8 as relations skirt pastel 35 skirt white 10 We use the value all is used to skirt all 53 represent aggregates dress dark 20 The SQL:1999 standard dress pastel 10 actually uses null values in dress white 5 place of all despite confusion dress all 35 with regular null values shirt dark 14 shirt pastel 7 shirt white 28 shirt all 49 pant dark 20 pant pastel pant white 5 pant all 27 a dark 62 all pastel 54 a white 48 all 164 Database System Concepts-5th Edition,Aug 26,2005 18.7 @Silberschatz,Korth and SudarshanDatabase System Concepts - 5 18.7 ©Silberschatz, Korth and Sudarshan th Edition, Aug 26, 2005 Relational Representation of Cross-tabs Cross-tabs can be represented as relations We use the value all is used to represent aggregates The SQL:1999 standard actually uses null values in place of all despite confusion with regular null values