Comments on: Oracle 11g: Reading alert log via SQL

By: Mike

Mike — Sat, 06 Jun 2009 15:43:52 +0000

@jared
But, 11g has HM commands to check integrity of data dictionary. E.g.
dbms_hm.run_check(‘Dictionary Integrity Check’,'my_run_01′);
select dbms_hm.get_run_report(‘my_run_01′) from dual;
So you can just knock out fixing (hacking) those damaged rowid. ;)

By: Tanel Poder

Tanel Poder — Mon, 20 Apr 2009 08:43:59 +0000

Yep Jared you’ve got a valid point. Statspack also creates some X$ aliases (and some other monitoring tools too). I like your idea of having a PL/SQL package instead…

I don’t recommend to just create x$ aliases for all tables in production (I will also add a warning to my script which allows you to do so). Just for the sake of not “disturbing” Oracle if it’s not needed…

By: Jared

Jared — Mon, 06 Apr 2009 20:39:10 +0000

Regarding creating your own v$ view on top of x$ tables:

That come become something of a nuisance after an upgrade.

There are instances when the internal structure of the data dictionary changes during the upgrade, causing the custom view to be invalid.

In some cases, attempts to recompile the view will cause and ORA-600 [12600].

Attempts to drop the view will cause the same error, and it will in fact be impossible to drop the view, short of hacking the data dictionary.

I have a few databases with X_$KCBCBH and X_$KCBRBH views that cannot be dropped. Mostly just an annoyance.

By: Tanel Poder

Tanel Poder — Fri, 27 Mar 2009 17:48:14 +0000

Yes!

Look into DBMS_REDEFINITION

Note that this kind of stuff should be very carefully, thoroughly and repeatedly tested before trying it out live!

Also, if you rename the table – how do you expect the SQL to continue working (are you creating a view or synonym instead?)

So test the hell out of this approach before even thinking about running it in live (with heavy production-like activity going on in your test db). And then test some more.

By: Senthil

Senthil — Fri, 27 Mar 2009 17:37:10 +0000

Hi Tanel,

Congrats for becoming oracle ACE :)

- We have a requirement in one of our tables in our production db like this , The table name should be renamed and a column should be dropped.The table is a highly active table , with lots of sessions accessing that table continuously.It’s not possible to take any down time for this activity. Is it possible to do these modifications in that table when all the transactions are happening?

— regards,

By: Pythian Group - Blog

Pythian Group - Blog — Fri, 27 Mar 2009 17:17:41 +0000

[...] Staying with SQL and all the wonderful things you can do with it, Tanel Poder looks into one of its capacities in Oracle 11g: reading the alert log via SQL. [...]

By: Marco Gralike

Marco Gralike — Tue, 24 Mar 2009 21:17:42 +0000

In the end the exercise was cool, but reading your post you start wondering why Laurent and me did it

;-)

http://laurentschneider.com/wordpress/2008/04/alert-log-in-xml-format.html

By: Tanel Poder

Tanel Poder — Mon, 23 Mar 2009 09:52:11 +0000

Yeah for now you can create your own “V$” table on top of the X$ one and grant access on that to whoever needs to acces it.

By: Mladen Gogala

Mladen Gogala — Mon, 23 Mar 2009 09:06:21 +0000

Unfortunately, this is X$ table, which means that it is only readable when connected as SYSDBA. Nice thing, but it would be much more useful as a documented V$ table. Hopefully, Oracle Corp. will give us that, too.

By: Dion Cho

Dion Cho — Mon, 23 Mar 2009 00:32:26 +0000

Valueable info!