create table funding_requests (       request_id	      integer primary key,       requestor	      varchar(20),       program_name	      varchar(20),       -- in billions of dollars       amount		      number,       purpose		      varchar(50));insert into funding_requests values(1,'entitlement','Medicare',248,'Health care for old folks');insert into funding_requests values(2,'entitlement','Medicaid',280,'Health care for poor folks');insert into funding_requests values(3,'George W','Prescription Drugs',400,'Welfare for drug companies');select * from funding_requests;column request_id format 99column requestor format a12column program_name format a10column amount format 9999column purpose format a20select * from funding_requests;---- cambia a win2commit;select sum(amount) from funding_requests;insert into funding_requests values(4,'George W','IraqAid',87,'Rebuild Iraq');select sum(amount) from funding_requests;---- cambia a win2commit;update funding_requestsset amount = 500where request_id = 3;---- cambia a win2commit;---- cambia a win2update funding_requestsset amount = 125where request_id = 4;---- cambia a win2commit;-------------- VENTANA 2 describe funding_requestsselect * from funding_requests;--- cambia a win1select sum(amount) from funding_requests;insert into funding_requests values(4,'Democrats','Edumucation',75,'Votes from teacher unions');--- ** gran idea:  los redactores nunca esperan a nadie a no ser que se trate de escritores intentando       actualizar la misma fila o insertar una nueva con la misma clave principal--- consultar    http://download-west.oracle.com/docs/cd/B10501_01/server.920/a96524/c21cnsis.htm#2570    para ver el funcionamiento; también http://download-west.oracle.com/docs/cd/B10501_01/appdev.920/a96590/adg08sql.htm#2655--- cambia a win1select * from funding_requests where request_id = 3;update funding_requests set amount = 450where request_id = 3;--- cambia a win1set transaction isolation level serializable;update funding_requestsset amount = 80where request_id = 4;--- cambia a win1