Question

I’m working on a pl sql stored procedure.
What I need is to do a select, use a cursor and for every record build a string using values.
At the end I need to write this into a file.
I try to use dbms_output.put_line(“toto”) but the buffer size is to small because I have about 14 millions lines.
I call my procedure from a unix ksh.
I’m thinking at something like using “spool on” (on the ksh side) to dump the result of my procedure, but I don’ know how to do it (if this is possible)

Anyone has any idea?

Answer 1

Unless it is really necessary, I would not use a procedure.

If you call the script using SQLPlus, just put the following into your test.sql (the SETs are from SQLPlus FAQ to remove noise):

SET ECHO OFF
SET NEWPAGE 0
SET SPACE 0
SET PAGESIZE 0
SET FEEDBACK OFF
SET HEADING OFF
SET TRIMSPOOL ON
SET TAB OFF

Select owner || ';' || object_name
From all_objects;

QUIT

and redirect output to a file (test.txt):

sqlplus user/passwd@instance @ test.sql > test.txt

---

If you really need to do stuff in PL/SQL, consider putting that into a function and call it per record:

Create Or Replace Function calculate_my_row( in_some_data In Varchar2 )
  Return Varchar2
As
Begin
  Return in_some_data || 'something-complicated';
End calculate_my_row;

Call:

Select owner || ';' || calculate_my_row( object_name )
From all_objects;

Performance could suffer, but it should work. Make sure, that what you try can’t be done in pure SQL, though.

---

Reading your comment I think that Analytic Function Lag is what you need.

This example appends * in case the value of val has changed:

With x As (
      Select 1 id, 'A' val FROM dual
Union Select 2 id, 'A' val FROM dual
Union Select 3 id, 'B' val FROM dual
Union Select 4 id, 'B' val FROM dual
)
--# End of test-data
Select
  id,
  val,
  Case When ( val <> prev_val Or prev_val Is Null ) Then '*' End As changed
From (
  Select id, val, Lag( val ) Over ( Order By id ) As prev_val
  From x
)
Order By id

Returns

        ID V C
---------- - -
         1 A *
         2 A  
         3 B *
         4 B