for all DBA Master..

at my table i have some index MYSS1 ( Create index myss1 on myss(p_tgl,p_lok,p_meja,p_flag) buit i dont have Primary Key.
every application run i used command : "ALTER TABLE MYSS1 ACTIVE"
   
i have command sql at my aplication :
  " select p_meja,p_sku,p_sell,p_disc,sum(p_qty),p_tax from myss where p_tgl='01/01/2009' and P_LOK='01' AND p_meja='R301' AND P_FLAG =' ' order by  p_meja,p_sku,p_sell,p_disc PLAN (myss order myss1) group by p_meja,p_sku,p_sell,p_disc "

for starting this week sometime i can not load this record data. but
after i am run sql : 'ALTER INDEX MYSS1 ACTIVE'
I can load this data again.

why ?
something wrong at my sql command and my structure table ?
thanks for the solution... and thanks....





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