/*  Chapter 2  */

/*  C02S2D01.sas  */

libname ia 'c:\workshop\winsas\effi';

options fullstimer msglevel = i;

/* Create indexes in the DATA step:  */

data Schedule (index = (RouteStart  
                                      DteFlt = (ScheduledDate FlightNumber) / unique));
  set ia.Schedule;
run;

/* Create indexes in PROC DATASETS:  */

proc datasets lib = ia;
  modify Schedule;
     index create RouteStart;
     index create DteFlt = (Scheduled Date FlightNumber) / unique;
  run;
quit;

/* Delete indexes in PROC DATASETS:  */

proc datasets lib = ia;
  modify Schedule;
     index delete RouteStart ;
  run;
quit;


/* Create indexes in PROC SQL:  */

proc sql;
     create index RouteStart
        on ia.Schedule (RouteStart);
     create unique index DteFlt
        on ia.Schedule (Scheduled Date FlightNumber);
quit;

/* Delete indexes in PROC SQL:  */

proc sql;
     drop index RouteStart
        from ia.Schedule;
quit;