Improve performance on specific PL/SQL code

Question

In these three querys there are identical "select" statements in the "where" sections of the querys.
SELECT sum(num_tit_par)
INTO posicion
FROM posi_hoy_rbo
WHERE fec_pos = fecha
and enti_cli in (select cod_int_ent from enti_rbo where enti_efe = entidad);
SELECT sum(mctasald)
INTO saldo_cuenta
FROM gbinmcta_rbo
WHERE mctafech = fecha
and mctaclav in (select cod_int_ent from enti_rbo where enti_efe = entidad);
SELECT sum(tarjdisp)
INTO saldo_tarjeta
FROM gbintarj_rbo
WHERE tarjfech = fecha
and tarjclav in (select cod_int_ent from enti_rbo where enti_efe = entidad);
Is there any way, using PL/SQL code, to store the results of this "select" statement in a kind of variable (varrays, nested tables...)
and then use this variable on the "where" clauses?. If it exists, could someone explain it in detail?
This way, I suppose that this "select" should be only once executed and the performance improved.
Thank You Very Much

Answer 1

Daniel,
I happened to have this code, which I posted in the past. simplified
You could ignore the creation of package and you could include the functionality of procedure A into procedure B in the following example,-- create a SQL type
SQL> create or replace type numTyp as table of number
  2  /
Type created.
SQL> create or replace package test_pkg as
  2    procedure B;
  3  end;
  4  /
Package created.
SQL> create or replace package body test_pkg as
  2 
  2       numArray numTyp := numTyp(); -- initialize
  3 
  3       procedure A Is -- Fills the array
  4       Begin
  5           numArray.extend(2);
  6           numArray(1) := 10;
  7           numArray(2) := 20;
  8       End;
  9   
10       procedure B Is
11       Begin
12          A; -- call to procedure A
13          For rec in (select empno from my_emp where deptno IN
14                       (Select a.column_value  val
15                          From THE ( select cast(numArray as numTyp) from dual ) a))
16          loop
17             dbms_output.put_line(rec.empno);
18          end loop;
19       end;
20  end;
21  /
Package body created.
SQL> exec test_pkg.B;
7782
7839
7934
7369
7876
7902
7788
7566
PL/SQL procedure successfully completed.Not a great example, but it shows how to use SQL type nested tables to use in SQL join operations. Hope it helps.
Thx,
Sri