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Thread: Cluster / Tablespace ?

Cluster / Tablespace ?

From
"Nico Callewaert"
Date:
Hi,
 
Maybe my question is too simple...
Anyway, I'm coming from a Firebird background where we just talk about a database file.  I read that PostgreSQL is working with a database cluster.  I don't know exactly the meaning of that and I didn't find a well explaining answer on the internet.  And is there a difference between a cluster and a tablespace ?
 
Many thanks in advance, Nico

Re: Cluster / Tablespace ?

From
Andreas Wenk
Date:
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Nico Callewaert schrieb:
> Hi,
>
> Maybe my question is too simple...
> Anyway, I'm coming from a Firebird background where we just talk about a
> database file.  I read that PostgreSQL is working with a database
> cluster.  I don't know exactly the meaning of that and I didn't find a
> well explaining answer on the internet.
Hi,

a database cluster can have more than one database. You build a cluster with initdb. In
this cluster you create databases with CREATE DATABASE.

http://www.postgresql.org/docs/8.3/interactive/app-initdb.html

 And is there a difference
> between a cluster and a tablespace ?

Tablespaces are the possibility to define a location where your database objects are
placed on your hd.

http://www.postgresql.org/docs/8.3/interactive/manage-ag-tablespaces.html

> Many thanks in advance, Nico

For more info refer to the documentation ;-)

http://www.postgresql.org/docs/

Cheers

Andy

- ----------------------------------
St.Pauli - Hamburg - Germany

Andreas Wenk
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Re: Cluster / Tablespace ?

From
Carol Walter
Date:

On Feb 10, 2009, at 7:56 AM, Nico Callewaert wrote:

Hi,
 
Maybe my question is too simple...
Anyway, I'm coming from a Firebird background where we just talk about a database file.  I read that PostgreSQL is working with a database cluster.  I don't know exactly the meaning of that and I didn't find a well explaining answer on the internet. 

Postgres uses this to distinguish between the postgres database engine or software and the databases that are created and maintained there.  When we talk about the postgres database we generally mean the engine or software, unless we say something like "I have a database that ..."  In the latter case, we're probably talking about a database in the cluster.  I cluster can be a single database.

And is there a difference between a cluster and a tablespace ?
 
Many thanks in advance, Nico

Re: Cluster / Tablespace ?

From
"Nico Callewaert"
Date:
Thanks a lot....
----- Original Message -----
Sent: Tuesday, February 10, 2009 2:36 PM
Subject: Re: [NOVICE] Cluster / Tablespace ?


On Feb 10, 2009, at 7:56 AM, Nico Callewaert wrote:

Hi,
 
Maybe my question is too simple...
Anyway, I'm coming from a Firebird background where we just talk about a database file.  I read that PostgreSQL is working with a database cluster.  I don't know exactly the meaning of that and I didn't find a well explaining answer on the internet. 

Postgres uses this to distinguish between the postgres database engine or software and the databases that are created and maintained there.  When we talk about the postgres database we generally mean the engine or software, unless we say something like "I have a database that ..."  In the latter case, we're probably talking about a database in the cluster.  I cluster can be a single database.

And is there a difference between a cluster and a tablespace ?
 
Many thanks in advance, Nico