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I enjoyed the answers and questions about hidden features in sql server
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Since Apex is now part of every Oracle database, these Apex utility functions are useful even if you aren't using Apex:
SQL> declare
2 v_array apex_application_global.vc_arr2;
3 v_string varchar2(2000);
4 begin
5 -- Convert delimited string to array
6 v_array := apex_util.string_to_table('alpha,beta,gamma,delta', ',');
7 for i in 1..v_array.count
8 loop
9 dbms_output.put_line(v_array(i));
10 end loop;
11 -- Convert array to delimited string
12 v_string := apex_util.table_to_string(v_array,'|');
13 dbms_output.put_line(v_string);
14 end;
/ alpha beta gamma delta alpha|beta|gamma|delta PL/SQL procedure successfully completed.
The Buffer Cache Hit Ratio is virtually meaningless as a predictor of system efficiency
You can view table data as of a previous time using Flashback Query, with certain limitations.
Select * from my_table as of timestamp(timestamp '2008-12-01 15:21:13')
11g has a whole new feature set around preserving historical changes more robustly.
The OVERLAPS predicate is undocumented.
http://oraclesponge.wordpress.com/2008/06/12/the-overlaps-predicate/
If you get the value of PASSWORD
column on DBA_USERS
you can backup/restore passwords without knowing them:
ALTER USER xxx IDENTIFIED BY VALUES 'xxxx';
Bypass the buffer cache and read straight from disk using direct path reads.
alter session set "_serial_direct_read"=true;
Causes a tablespace (9i) or fast object (10g+) checkpoint, so careful on busy OLTP systems.
Q: How to call a stored with a cursor from TOAD?
A: Example, change to your cursor, packagename and stored proc name
declare cursor PCK_UTILS.typ_cursor;
begin
PCK_UTILS.spc_get_encodedstring(
'U',
10000002,
null,
'none',
cursor);
end;
1- The Model Clause (available for Oracle 10g and up)
2- WM_CONCAT for string aggregation
Left trim is doing by Oracle automatically. But not Right Trim
Left Trim Ex:
------------------------
SELECT length('ABC ') ,length('ABC')
FROM DUAL
WHERE 'ABC ' = 'ABC'
LENGTH('ABC') LENGTH('ABC')_1
-------------------- ---------------------------------
7 3
Right Trim Ex:
-------------------------
SELECT length(' ABC') ,length('ABC')
FROM DUAL
WHERE ' ABC' = 'ABC'
Output:
No rows returned
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