kwatog

I got tangled with a problem on the datatype LONG in Oracle which is still being used in a number of applications. Siebel, is actually one of them. When I was tasked to extract some data from one of the tables in EIM using C++, I run into this problem.

I googled for answer and here’s what I got.

CREATE OR REPLACE FUNCTION LONG_TO_CHAR( in_rowid rowid,in_owner
varchar,in_table_name varchar,in_column varchar2)
RETURN varchar AS
text_c1 varchar2(32767);
sql_cur varchar2(2000);
--
begin
sql_cur := 'select '||in_column||' from
'||in_owner||'.'||in_table_name||' where rowid =
'||chr(39)||in_rowid||chr(39);
dbms_output.put_line (sql_cur);
execute immediate sql_cur into text_c1;

text_c1 := substr(text_c1, 1, 5000);
RETURN TEXT_C1;
END;


It’s pretty simple but unfortunately, we can’t do this without using function.

Example use:

SELECT MI_F_LONG_TO_CHAR(ROWID, 'SIEBEL','EIM_ORDER','ORD_X_COMMENTS')
FROM SIEBEL.EIM_ORDER


credit to Oracle Mag for this entry.

In case you only have SQL*Plus as your editor, you can use the following codes to show the execution plan of your query.

First Step : create plan
EXPLAIN PLAN FOR
SELECT field1, field2
FROM table;

Second Step: show results

SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY);


You will need the necessary privileges to execute this. You’ll also need to have the PLAN table. If not, you’ll have to create it as that’s the placeholder where execution plan is written.

This technique is important especially when you don’t have a GUI-based SQL editor like PL/SQL Developer or TOAD.

To see DB processes running on your Oracle DB, the code below can be used. Specially handy if you want to check which part of your package or stored procedure is taking time to execute. Indispensable for performance tuning.

SELECT sess.sid, sess.serial#, sess.sql_child_number, sess.sql_exec_id,
sess.process, sess.status, sess.username, sess.osuser, sess.program,
sess.schemaname, sql.sql_text
FROM v$session sess,
v$sql sql
WHERE sql.sql_id(+) = sess.sql_id
AND sess.type = 'USER'
--AND sess.osuser = 'yourwindowslogin';


Equivalent in SQL Server/Sybase

The equivalent command in Sybase or SQL Server is SP_WHO. However, the Oracle version provides more information.

For now, just this. I’ll provide additional details later. For additional fields, try to check the schema of v$session.

In case you are maintaining a pl/sql program developed by someone else and that program writes into a file, then basically that file is written to a folder/directory. And since the directories are saved in codes, you have to find the meaning (or location) of those codes. The code below will help you display the information required.

SELECT * FROM ALL_DIRECTORIES;

The query above will display all the directories accessible to the current user. They are folders in the server where you can write your output files. For some reason, I forgot about this twice already and had to scour the web to find it. The problem is, I also forgot the keywords. So, I’m writing it now.

To register new directories, you can follow the example below.

Example
create or replace directory mydir as 'c:\mydirectory';

To use, run the code below.

declare
f utl_file.file_type;
begin
f := utl_file.fopen('MYDIR', 'myfilename.txt', 'w');
utl_file.put_line(f, 'just another line text 1');
utl_file.put_line(f, 'just another line text 2');
utl_file.fclose(f);
end;