Re: 11g READ ONLY table
- From: Orlando L <oralrnr@xxxxxxxxx>
- To: Ric Van Dyke <ric.van.dyke@xxxxxxxxxx>
- Date: Wed, 14 Jul 2010 10:25:39 -0500
Thanks for the detailed answer Ric. I am trying to understand if there are
any gotchas with it. If it is as simple as that, I can relax and let the
application teams use this feature at a later date. I have seen the
application teams wanting to use features of Oracle at their whim in split
second notice. They want to turn on the feature one day but turn it off next
day and test it.
So my question is more of academic nature.
On Mon, Jul 12, 2010 at 5:08 PM, Ric Van Dyke <ric.van.dyke@xxxxxxxxxx>wrote:
> What I was trying to say and show was that it's just an attribute of the
> table. In the data dictionary there is likely a flag set in the table
> definition that show this table is READ ONLY. There would be no need to do
> anything with the individual extents.
>
> I assume you are thinking of READ ONLY table spaces and trying to see a
> connection between the two, I doubt there is any. Even READ ONLY table
> spaces just have an attribute in the data dictionary that make the table
> space as READ ONLY.
>
> To work with any object in the database you have to go thru the data
> dictionary. There is no need to set something like this at the individual
> extent level. Oracle might set something at the extent level I suppose, I
> haven't dumped blocks to check, but I see no need to do such a thing.
>
> Why didn't oracle do this earlier? Likely it never boiled up high enough
> on the priority list.
>
> Can I ask why this is important? Just for academic understanding or is
> there an issue you are trying to solve?
>
> Ric (the ROCK) Van Dyke
> Hotsos Enterprises Ltd
>
>
>
>
> -----Original Message-----
> From: oracle-l-bounce@xxxxxxxxxxxxx on behalf of Orlando L
> Sent: Tue 13-Jul-10 5:31 AM
> To: Mark W. Farnham
> Cc: oracle-l@xxxxxxxxxxxxx
> Subject: Re: 11g READ ONLY table
>
> THanks Mark, Connor and Rock. I was not looking for the syntax.
>
> I was looking for an explantion or maybe a paper on the internal details
> on how a read write table gets converted to read only. If table has extents
> all over a tablespace does Oracle mark the extent headers of the table as
> READ ONLY which prevents future updates?
> If it was a simple task I wonder why Oracle did not have this feature in
> older versions.
>
> I am also checking to see if people have used this feature in their
> envorinments. If so i want to see how efficient it is or any lessons
> learned
> type of things.
>
>
>
> On Fri, Jul 9, 2010 at 12:38 PM, Mark W. Farnham <mwf@xxxxxxxx> wrote:
>
> > . is what is confusing you. They are just different things.
> >
> >
> > ------------------------------
> >
> > *From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto:
> > oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *Mark W. Farnham
> > *Sent:* Friday, July 09, 2010 1:33 PM
> > *To:* oralrnr@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx
> > *Subject:* RE: 11g READ ONLY table
> >
> >
> >
> > Ric and Connor gave you the mechanics of this. But I suspect from the way
> > you phrased your question that the difference between a table that Oracle
> is
> > protecting from changes (READ ONLY table) and a tablespace that you don't
> > have to back up any more.
> >
> >
> >
> > mwf
> >
> >
> > ------------------------------
> >
> > *From:* oracle-l-bounce@xxxxxxxxxxxxx [mailto:
> > oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *Orlando L
> > *Sent:* Wednesday, July 07, 2010 11:20 AM
> > *To:* oracle-l@xxxxxxxxxxxxx
> > *Subject:* 11g READ ONLY table
> >
> >
> >
> > List
> >
> >
> >
> > Does anyone know how 11g is able to convert read write tables to READ
> ONLY
> > and back when the extents are all over mixed in with other tables in a
> > tablespace?
> >
> >
> >
> > Orlando.
> >
>
>
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