Is there any way of storing database other than the fixed data directory in postgres? I have a situation where I need to store database at any location irrespective of data directory.
You can add a tablespace.
A tablespace is basically a location to store databases and/or tables. You create a tablespace using CREATE TABLESPACE:
CREATE TABLESPACE mytablespace LOCATION '/path/to/some/location';
You can then create tables directly in that tablespace:
CREATE TABLE whatever (thing integer) TABLESPACE mytablespace;
Or set the default tablespace:
SET default_tablespace = mytablespace;
You can also set the default tablespace at database creation time:
CREATE DATABASE mydatabase TABLESPACE mytablespace;
You are looking for the 'Data Directory' in linux for example its in
/usr/local/pgsql/data
if you install from source code. Each distribution is different though, try reading up on
File Locations in postgres and Creating a Database Cluster
also try using the query
show data_directory;
in windows try looking around
C:\Program Files (x86)\PostgreSQL\[VERSION]\data\global
Related
I have a situation in which summing the size of the tables in a tablespace (using pg_class among others) reveals that there is 550G of datafiles in a particular tablespace in a particular database.
However, there is 670G of files in that directory on the server.
FWIW, I don't know how that can be. No files have been written to that directory via any mechanism other than Postgres. My best guess is perhaps the database crashed while an autovacuum was going on, leaving orphan files laying around...does that sound plausible?)
SO, I've worked out a way, by reading the contents of a ls command into the database, strip off the numeric extensions for tables > 1G in size, and compare them with the contents of pg_class, and have, in fact, found about 120G of files not reflected in pg_class.
My question is, is it safe for me to delete these files, or could they be in active use by the database but not reflected in pg_class?
Do not manually delete files in the PostgreSQL data directory.
This is not safe and will corrupt your database.
The safe way to purge any files that don't belong to the database is to perform a pg_dumpall, stop the server, remove the data directory and the contents of all tablespace directories, breate a new cluster with inindb and restore the dump.
If you want to investigate the issue, you could try to create a new tablespace and move everything from the old to the new tablespace. I will describe that in the rest of my answer.
Move all the tables and indexes in all databases to the new tablespace:
ALTER TABLE ALL IN TABLESPACE oldtblsp SET TABLESPACE newtblsp;
ALTER INDEX ALL IN TABLESPACE oldtblsp SET TABLESPACE newtblsp;
If oldtblsp is the default tablespace of a database:
ALTER DATABASE mydb SET TABLESPACE newtblsp;
Then run a checkpoint:
CHECKPOINT;
Make sure you forgot no database:
SELECT datname
FROM pg_database d
JOIN pg_tablespace s
ON d.dattablespace = s.oid
WHERE s.spcname = 'oldtblsp';
Make sure that there are no objects in the old tablespace by running this query in all databases:
SELECT t.relname, t.relnamespace::regnamespace, t.relkind
FROM pg_class t
JOIN pg_tablespace s
ON t.reltablespace = s.oid
WHERE s.spcname = 'oldtblsp';
This should return no results.
Now the old tablespace should be empty and you can
DROP TABLESPACE oldtblsp;
If you really get an error
ERROR: tablespace "tblsp" is not empty
there might be some files left behind.
Delete them at your own risk...
friends,
I have a .dump file of oracle 10G that I have to restore with IMP in oracle 11G. but I don't know how to do it so that you don't put the tables inside the tablespace of the system.
The command I'm using is
imp system/passw file=backup_dpz.dmp fromuser=pepe touser=mario
The problem is that the origin has the tables in the tablespace of system and I want that the destiny has it inside the tablespace of mario.
Thank you
Given a database dump how to specify a tablespace to be used by all tables during restore? The database has multiple tablespaces used by its table. Old tablespaces should be ignored (they are not relevant on new computer) and all tablespaces my by replaced by a new one.
dump with "--no-tablespaces" parameter to have tablespaces-free dump - but you can also use the same parameter on pg_restore if you cannot change dump commands
set global parameter "default_tablespace" on target DB to what is needed for restore (for example by using alter database xxxxx set DEFAULT_TABLESPACE='xxx')
run all pg_restore tasks
if necessary reset default_tablespace to original value
I have created a tablespace named hdd_tablespace and I wan't all new databases to be automatically created there. Basically when I execute:
CREATE DATABASE FOO;
I want this database to be created in hdd_tablespace.
I have updated postgresql.conf with:
default_tablespace = 'hdd_tablespace'
However, new databases are still created in pg_default.
Actually it turned out I had also to update template1 database that is a template database.
I had to;
ALTER DATABASE template1 SET TABLESPACE hdd_tablespace;
I am trying to create a PG db in a specified location. According to the docs here, I must use the LOCATION flag. However, when I run CREATE DATABASE (from the pgsql CLI), I get the following warning:
WARNING: LOCATION is not supported anymore
HINT: Consider using tablespaces instead.
However, the PG documentation on TABLESPACES does not show how it can be used to create a database in a specific directory. What is the required syntax to do this?
You would need to do this in 2 steps:
Create Tablespace examples for which you can see in the link
Create Database
When you create tablespace you set it's location and then you can create multiple databases in the same tablespace if you choose to.
CREATE TABLESPACE fastspace LOCATION '/mnt/sda1/postgresql/data';
See the chapter about tablespaces in the manual.