Re: [GENERAL] combining db's- importing primary keys

2009-07-29 Thread Chris

Chris wrote:

Bob Gobeille wrote:


On Jul 29, 2009, at 8:26 AM, nha wrote:


Hello,

Le 29/07/09 15:02, Jasen Betts a écrit :

On 2009-07-27, Bob Gobeille  wrote:

I would like to combine multiple databases (same schema) into one
master db.   Does anyone know how I can reconcile all my primary and
foreign keys to maintain referential integrity.


prefix them all with something that's unique to their source database.

easy to say, hard to do.



A process (and solution) may be different whether:
-the master db will replace all other databases (ie. data manipulation
would directly perform on data managed by master db);
-or the master db will reflect a combined view of data hosted by all
other databases (ie. data manipulation would still perform on
distributed databases and master db would play a role of federated 
view);

-or both (data manipulation have to be manageable at the both side: on
master db and on distributed db).


In my immediate case, I'm simply combining 7 global databases into a 
single master.


Eventually, I would like to allow our (fossology.org) users to 
subscribe to data in other databases.  That is, allow

users to do periodic one-way batch updates from other servers.


Have you thought about schemas?

You can set up different users with different search paths so all the 
data's in one spot, and getting to another schema is easy enough. No 
changes necessary to the data itself, just the calling code.


Blah, ignore - I didn't read your first email properly :P

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Re: [GENERAL] combining db's- importing primary keys

2009-07-29 Thread Chris

Bob Gobeille wrote:


On Jul 29, 2009, at 8:26 AM, nha wrote:


Hello,

Le 29/07/09 15:02, Jasen Betts a écrit :

On 2009-07-27, Bob Gobeille  wrote:

I would like to combine multiple databases (same schema) into one
master db.   Does anyone know how I can reconcile all my primary and
foreign keys to maintain referential integrity.


prefix them all with something that's unique to their source database.

easy to say, hard to do.



A process (and solution) may be different whether:
-the master db will replace all other databases (ie. data manipulation
would directly perform on data managed by master db);
-or the master db will reflect a combined view of data hosted by all
other databases (ie. data manipulation would still perform on
distributed databases and master db would play a role of federated view);
-or both (data manipulation have to be manageable at the both side: on
master db and on distributed db).


In my immediate case, I'm simply combining 7 global databases into a 
single master.


Eventually, I would like to allow our (fossology.org) users to subscribe 
to data in other databases.  That is, allow

users to do periodic one-way batch updates from other servers.


Have you thought about schemas?

You can set up different users with different search paths so all the 
data's in one spot, and getting to another schema is easy enough. No 
changes necessary to the data itself, just the calling code.


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http://www.designmagick.com/


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Re: [GENERAL] combining db's- importing primary keys

2009-07-29 Thread nha
Hello,

Le 29/07/09 16:44, Bob Gobeille a écrit :
> 
> On Jul 29, 2009, at 8:26 AM, nha wrote:
> 
>> Hello,
>>
>> Le 29/07/09 15:02, Jasen Betts a écrit :
>>> On 2009-07-27, Bob Gobeille  wrote:
 I would like to combine multiple databases (same schema) into one
 master db.   Does anyone know how I can reconcile all my primary and
 foreign keys to maintain referential integrity.
>>>
>>> prefix them all with something that's unique to their source database.
>>>
>>> easy to say, hard to do.
>>>
>>
>> A process (and solution) may be different whether: [...cases...]
> 
> In my immediate case, I'm simply combining 7 global databases into a
> single master.
> 
> Eventually, I would like to allow our (fossology.org) users to subscribe
> to data in other databases.  That is, allow
> users to do periodic one-way batch updates from other servers.
> 
> Bob

In such a purpose (where asynchronous updates seem reasonable),
prefixing (as suggested by Jasen Bett) or adding server-based column to
current keys (as you mention thereafter) look like handy solutions.

Good plan.

Regards.

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Re: [GENERAL] combining db's- importing primary keys

2009-07-29 Thread Bob Gobeille


On Jul 29, 2009, at 8:26 AM, nha wrote:


Hello,

Le 29/07/09 15:02, Jasen Betts a écrit :

On 2009-07-27, Bob Gobeille  wrote:

I would like to combine multiple databases (same schema) into one
master db.   Does anyone know how I can reconcile all my primary and
foreign keys to maintain referential integrity.


prefix them all with something that's unique to their source  
database.


easy to say, hard to do.



A process (and solution) may be different whether:
-the master db will replace all other databases (ie. data manipulation
would directly perform on data managed by master db);
-or the master db will reflect a combined view of data hosted by all
other databases (ie. data manipulation would still perform on
distributed databases and master db would play a role of federated  
view);

-or both (data manipulation have to be manageable at the both side: on
master db and on distributed db).


In my immediate case, I'm simply combining 7 global databases into a  
single master.


Eventually, I would like to allow our (fossology.org) users to  
subscribe to data in other databases.  That is, allow

users to do periodic one-way batch updates from other servers.

Bob
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Re: [GENERAL] combining db's- importing primary keys

2009-07-29 Thread nha
Hello,

Le 29/07/09 15:02, Jasen Betts a écrit :
> On 2009-07-27, Bob Gobeille  wrote:
>> I would like to combine multiple databases (same schema) into one  
>> master db.   Does anyone know how I can reconcile all my primary and  
>> foreign keys to maintain referential integrity.
> 
> prefix them all with something that's unique to their source database.
> 
> easy to say, hard to do.
> 

A process (and solution) may be different whether:
-the master db will replace all other databases (ie. data manipulation
would directly perform on data managed by master db);
-or the master db will reflect a combined view of data hosted by all
other databases (ie. data manipulation would still perform on
distributed databases and master db would play a role of federated view);
-or both (data manipulation have to be manageable at the both side: on
master db and on distributed db).

Regards.
--
nha / Lyon / France.

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Re: [GENERAL] combining db's- importing primary keys

2009-07-29 Thread Bob Gobeille


On Jul 29, 2009, at 7:02 AM, Jasen Betts wrote:


On 2009-07-27, Bob Gobeille  wrote:

I would like to combine multiple databases (same schema) into one
master db.   Does anyone know how I can reconcile all my primary and
foreign keys to maintain referential integrity.


prefix them all with something that's unique to their source database.

easy to say, hard to do.


I can't believe this didn't occur to me.  All my primary keys are  
bigint's, but I could add a second field, a unique server number or  
name, and change my primary (and foreign) keys to the two column  
combination.  This would make it easy for new db's but I need to give  
some thought to see if there will be any hiccups migrating all the db's.


Many thanks Jasen.

Bob

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Re: [GENERAL] combining db's- importing primary keys

2009-07-29 Thread Jasen Betts
On 2009-07-27, Bob Gobeille  wrote:
> I would like to combine multiple databases (same schema) into one  
> master db.   Does anyone know how I can reconcile all my primary and  
> foreign keys to maintain referential integrity.

prefix them all with something that's unique to their source database.

easy to say, hard to do.

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