Do multiple "case" lines run against each line or is each run against the table ?
Do multiple "case" lines run against each line or is each run against the table ?
(OP)
I have informix 9.40.FC7. I have a 31 million line table that I extract information from. It takes up to 7 days now to finish. I don't know if it runs the 4 "case" lines against each row or if it is running 1 "case" against the 31 million rows and then moves to the next "case". Any ideas? I'd appreciate any assistance! Thanks!
CODE --> english
set isolation to dirty read; select f.patkey,f.invno,f.orderno,f.dx_orderno from findiag f into temp temp1 with no log; select t.patkey,t.invno, case when t.orderno = 1 then p.dxcode else " " end diag1, case when t.orderno = 2 then p.dxcode else " " end diag2, case when t.orderno = 3 then p.dxcode else " " end diag3, case when t.orderno = 4 then p.dxcode else " " end diag4 from temp1 t,patdiag p where t.patkey = p.patkey and t.dx_orderno = p.order_no and p.active = 'Y' into temp temp2 with no log; unload to 'trandiag1.txt' select * from temp2; unload to 'trandiag.txt' select t.patkey,t.invno,MAX(diag1) as d1, MAX(diag2) as d2, MAX(diag3) as d3, MAX(diag4) as d4 from temp2 t group by 1,2;