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[CDO] Evaluating CDO [message #948227] Wed, 17 October 2012 21:51 Go to next message
Michele Preti is currently offline Michele PretiFriend
Messages: 14
Registered: October 2012
Junior Member
Hi all,
i'm evaluating cdo for a new project, and after some tests i come with some perplexities.

- I don't need audit, and don't want it, i just need the last status of an object and this way audit is a waste of space.

- In my tests, when i delete an object, it's still in the db (i'm using mysql) but with a negative version. This is again a waste of space. It's always so or just for JDBC ?

- I will need clone or workspace, but this mean i'll need branches (is it?), and...branches need audit (is it?). So...a huge waste of space.

- The database structure store a lot of data around my objects (7 columns for each object-table, and the cdo_objects table), this near double the size of my data. But this would be a minor issue.

The point is: i'm missing something or i'm better not using CDO for my data mdel ?
Re: [CDO] Evaluating CDO [message #948515 is a reply to message #948227] Thu, 18 October 2012 05:15 Go to previous messageGo to next message
Eike Stepper is currently offline Eike StepperFriend
Messages: 5574
Registered: July 2009
Senior Member
Am 17.10.2012 23:51, schrieb Michele Preti:
> Hi all,
> i'm evaluating cdo for a new project, and after some tests i come with some perplexities.
>
> - I don't need audit, and don't want it, i just need the last status of an object
Then switch auditing off.

> and this way audit is a waste of space.
What way?

> - In my tests, when i delete an object, it's still in the db (i'm using mysql) but with a negative version. This is
> again a waste of space.
Yes. It's a DBStore "bug":

351068: [DB] Consider deleting old revisions when audits disabled
https://bugs.eclipse.org/bugs/show_bug.cgi?id=351068

I really want to work on it soon.

> It's always so or just for JDBC ?
See above. All storage aspects are IStore-specific.

> - I will need clone or workspace, but this mean i'll need branches (is it?),
It is. A CDOWorkspace though creates a local (internal) non-auditing repository and IIRC the master can be non-branching
but not non-auditing.

> and...branches need audit (is it?).
It is.

> So...a huge waste of space.
If you say so.

> - The database structure store a lot of data around my objects (7 columns for each object-table, and the cdo_objects
> table), this near double the size of my data. But this would be a minor issue.
How large is your data?

> The point is: i'm missing something or i'm better not using CDO for my data mdel ?
I can deliver facts about CDO. It's up to you to decide.

Cheers
/Eike

----
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http://thegordian.blogspot.com
http://twitter.com/eikestepper
Re: [CDO] Evaluating CDO [message #948808 is a reply to message #948515] Thu, 18 October 2012 11:50 Go to previous messageGo to next message
Michele Preti is currently offline Michele PretiFriend
Messages: 14
Registered: October 2012
Junior Member
ok, maybe I've been a little catastrophic.

> Then switch auditing off.
I'll need it for clone or workspace, so i can't switch it off.

> I really want to work on it soon.
If it's only a temporary bug, i can live with it.
Or can you suggest a more suitable Store ? (i only have experience with RDBMS but i can experiment)

> the master can be non-branching but not non-auditing.
audit is a big problem...can i at least periodically "compact" the database, removing all older versions ? (if so it could be bearable)

> How large is your data?
for now it is about 50.000 objects (with 5 or 8 attributes each) and it will grow 100 or 200 a day.

I apologize for my first post, but after believing to have found in CDO the solution to my problems, I felt a little frustrated by new ones.
Thanks a lot for your answer.

[Updated on: Thu, 18 October 2012 11:51]

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Re: [CDO] Evaluating CDO [message #948890 is a reply to message #948808] Thu, 18 October 2012 13:41 Go to previous message
Eike Stepper is currently offline Eike StepperFriend
Messages: 5574
Registered: July 2009
Senior Member
Am 18.10.2012 13:50, schrieb Michele Preti:
> ok, maybe I've been a little catastrophic.
>
>> Then switch auditing off.
> I'll need it for clone or workspace, so i can't switch it off.
>
>> I really want to work on it soon.
> If it's only a temporary bug, i can live with it.
> Or can you suggest a more suitable Store ? (i only have experience with RDBMS but i can experiment)
The HibernateStore doesn't suffer from this problem but it doesn't support branching. Hence no offline modes.

>
>> the master can be non-branching but not non-auditing.
> audit is a big problem...can i at least periodically "compact" the database, removing all older versions ? (if so it
> could be bearable)
I've never tried it but it may be possible with SQL. Make sure that you don't delete data that is still needed by clone
repositories to merge up their "local" changes.

>
>> How large is your data?
> for now it is about 50.000 objects (with 5 or 8 attributes each) and it will grow 100 or 200 a day.
If your repository doesn't run on a mobile phone I wouldn't invest a lot of thought into whether twice the space needed
for 50000 objects hurt or not. Maybe I can better understand if you tell me the DB sizes with and without the CDO system
columns.

> I apologize for my first post, but after believing to have found in CDO the solution to my problems, I felt a little
> frustrated by new ones.
Accepted ;-)

Cheers
/Eike

----
http://www.esc-net.de
http://thegordian.blogspot.com
http://twitter.com/eikestepper
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