On Fri, May 4, 2012 at 3:31 PM, Siva Palanisamy <siva_p@xxxxxxx> wrote:
Hi Raghavendra,
Is it sure that we can copy only the data of Postgresql from one disk to other seamlessly and then I can reuse the content without any hassle? If so, tablespace is what I should create first?
Please clarify me on this.
Thanks & Regards,
Siva.
Yes, using tablespace, you can move object files across disks. Here is small example, I have done on my local box but you can tweak as per your tablespace locations.
First I place object in one tablespace and moved it another tablespace.
postgres=# create tablespace space1 location '/opt/PostgreSQL/9.1/tspace';
CREATE TABLESPACE
postgres=# create table foo(id int) tablespace space1;
CREATE TABLE
postgres=# \d foo
Table "public.foo"
Column | Type | Modifiers
--------+---------+-----------
id | integer |
Tablespace: "space1"
postgres=# insert into foo select generate_series(1,10000);
INSERT 0 10000
postgres=# \dt+ foo
List of relations
Schema | Name | Type | Owner | Size | Description
--------+------+-------+----------+--------+-------------
public | foo | table | postgres | 384 kB |
(1 row)
postgres=# select pg_tablespace_size('space1');
pg_tablespace_size
--------------------
397312
(1 row)
Now create a new one and move it.
postgres=# create tablespace new_space location '/opt/PostgreSQL/9.1/newspace';
CREATE TABLESPACE
postgres=# alter table foo set tablespace new_space;
ALTER TABLE
postgres=# \d foo
Table "public.foo"
Column | Type | Modifiers
--------+---------+-----------
id | integer |
Tablespace: "new_space"
postgres=# select pg_tablespace_size('new_space');
pg_tablespace_size
--------------------
397312
(1 row)
---
Regards,
Raghavendra
EnterpriseDB Corporation
