Laurent Schneider

I noticed a side effect of SET LONGC today…

The default setting for LONG and LONGC is 80. This is quite annoying when you SELECT TEXT FROM ALL_VIEWS as it truncates the text to 80.

So why not setting it to the maximum?

Let’s first demo the usage of LINESIZE, LONG and LONGCHUNKSIZE

SQL> create view v as select 
'12345678910111213141516171819202' x 
from dual;

View created.

SQL> set lin 80 long 20 longc 20
SQL> select text from user_views where view_name='V';

TEXT
--------------------
select '123456789101

SQL> set lin 80 long 1000000000 longc 20
SQL> select text from user_views where view_name='V';

TEXT
--------------------
select '123456789101
11213141516171819202
' x from dual

SQL> set lin 80 long 1000000000 longc 1000000000
SQL> select text from user_views where view_name='V';

TEXT
-----------------------------------------------------
select '12345678910111213141516171819202' x from dual

When I use a LONG setting smaller than the length of the TEXT column, I got it truncated. When I use a huge LONG setting but a LONGCHUNKSIZE setting smaller than the length of the TEXT column, I got it wrapped. When both are huge, it seems I am getting the expecting result. So why not setting SET LONG 2000000000 LONGC 2000000000 in your login.sql ?

Have a look :

SQL> SET LONG 10 LONGC 10 LIN 80 TIMI ON
SQL> SELECT TO_CLOB('X') FROM DUAL;

TO_CLOB('X
----------
X

Elapsed: 00:00:00.01
SQL> SET LONG 1000000 LONGC 1000000 LIN 80 TIMI ON
SQL> SELECT TO_CLOB('X') FROM DUAL;

TO_CLOB('X')
------------
X

Elapsed: 00:00:00.00
SQL> SET LONG 1000000000 LONGC 1000000000 LIN 80 TIMI ON
SQL> SELECT TO_CLOB('X') FROM DUAL;

TO_CLOB('X')
------------
X

Elapsed: 00:00:02.06

2 seconds to select 1 character from dual !

I also tried to set it to 2000000000 but since I do not have 2Gb of free memory my notebook started swapping so badly I could not even move my mouse