Need Help in Improving Performace of PLSQL Code

Question

Hello Gurus,
I am very new to PL/SQL Coding. i had to design a code that takes values from 3 tables and fills the empty 4th table.
Table 1 : IDH(primary key),Table 2 :IDH(primary key) and Table 3 where IDH exists but not a Primary key(means has multiple values for each IDH)
So my approach was i created a STORED PROCEDURE as below
1. Create a cursor joining Table1 and Table 2
2. Iterate over the Cursor, for Each IDH create one more cursor over Table 3 and Calculate some values.
3. insert into the New Table.
But this seems to take a long time (more than 5 hours)
Can you please help me in optimizing this solutions ?
Thanks,
Ganesh

Answer 1

BRAND table : IDH,BRAND,SUBBRAND -> IDH Primary key
MARKET table : IDH,MARKET,VARIANT -> IDH Primary key
MAT table : col1,IDH,col4,col5,col15 -> no primary key here * redundant table
New table needs to be created as follows
LEGEND table : IDH,BRAND,SUBBRAND,MARKET,VARIANT,CODE,EAN
now its easy to get IDH,BRAND,SUBBRAND,MARKET,VARIANT into the LEGEND table (just a join result will give)
but CODE is calculated as follows
FOr an IDH in MAT
     if col4 contains 'OLDKEZ' then
          CODE:= col5;
EAN is calculated as follows
FOr an IDH in MAT
     if col1 contains 'MARA' then
          CODE:= col15;
this i am accomplishing by using 2 cursors (nested), which takes a long time !!!
Can you give any inputs ?