Introduction to Database Systems

1 Write the relational algebra statement which will select all tuples from the PC table which have a price $800. 2. Display the table which is the answer to the relational algebra query of question 1 The relation PC model |speedramhdprice 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 2.66 1024 250 2114 2.10512250 995 1.42 512 80 478 2.80 1024 250 649 3.20 512250 630 3.20 1024 320 1049 2.20 1024 200510 2.20 2048 250 770 2.00 1024 250 650 2.80 2048 300 770 1.86 2048 160 959 2.80 1024 160 649 3.06 512 80529 The relation Laptop model |speedramhdscreen price 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2.00 2048 240 1.73 1024 80 1.80 51260 2.00512 60 2.16 1024 120 2.00 2048 80 1.83 1024 120 1.60 1024 100 1.60 51280 2.00 2048 160 20.13673 17.0949 15.4 549 13.31150 17.0 2500 15.4 1700 13.3 1429 15.4900 14.1 680 15.4 2300 The relation Printer model otypeprice 3001 tru ink-jet 3002 falselaser 3003 true lase 239 899 120 120 100 200 true ink-jet 3005 false laser 3006 tru ink-jet 3007 true lase