create table OPS
(OPS_ID integer not null default autoincrement,
DAT       date                           not null,
CST_ID  integer,
       .
       .
       .
primary key (OPS_ID));

create table COR (
    cor_id    integer  not null default autoincrement,
    OPS_ID  integer,
    DB        char( 5 )             not null,
    CR        char( 5 )             not null,
    S_P       numeric( 12 , 2 )    not null default  0 . 0 ,
       .
       .
       .
    primary key (cor_id)
);

alter tableCOR
   add constraint foreign key (OPS_ID)
      references OPS (OPS_ID)
      on update cascade
      on delete cascade;

SELECT OPS.DAT,
	   (select sum(s_p) from cor c 
           		where c.ops_id=ops.ops_id and c.db ='3611' ) as SUM_DB,
	   (select sum(s_p) from cor c 
		where c.ops_id=ops.ops_id and c.cr ='3611' ) as SUM_CR,
	(select name from cst where cst_id= 350 ),
   .
   .
   .
from ops
 where  OPS.DAT between dbeg and dend ) and OPS.CST =  350 
    and (SUM_DB<> 0  OR SUM_CR<> 0 )

exists(select  1  from cor where  cor.ops_id=ops.ops_id AND (cr ='3611' or db ='3611'))

SELECT OPS.DAT, 
  sum(IF c.db = '3611' THEN c.s_p ELSE  0  ENDIF) AS SUM_DB,
  sum(IF c.cr = '3611' THEN c.s_p ELSE  0  ENDIF) AS SUM_CR
from ops
  inner join cor c ON c.ops_id=ops.ops_id AND (c.db = '3611' OR c.cr = '3611')
where  (OPS.DAT between dbeg and dend) 
  and OPS.CST =  350 

 input into tmp_ops from ...
-- потом некоторая чистка и обработка
-- а следом заливка в рабочую таблицу
 insert into ops(ops_id,ops_date...)
 select ops_id,ops_date... from tmp_ops
 where ...