diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/manage-ag.sgml | 21 | ||||
| -rw-r--r-- | doc/src/sgml/ref/create_tablespace.sgml | 8 |
2 files changed, 27 insertions, 2 deletions
diff --git a/doc/src/sgml/manage-ag.sgml b/doc/src/sgml/manage-ag.sgml index b44d521ba69..78ec509a8b5 100644 --- a/doc/src/sgml/manage-ag.sgml +++ b/doc/src/sgml/manage-ag.sgml @@ -379,17 +379,34 @@ dropdb <replaceable class="parameter">dbname</replaceable> expensive, slower disk system. </para> + <warning> + <para> + Even though located outside the main PostgreSQL data directory, + tablespaces are an integral part of the database cluster and + <emphasis>cannot</emphasis> be treated as an autonomous collection + of data files. They are dependent on metadata contained in the main + data directory, and therefore cannot be attached to a different + database cluster or backed up individually. Similarly, if you lose + a tablespace (file deletion, disk failure, etc), the database cluster + might become unreadable or unable to start. Placing a tablespace + on a temporary file system like a ramdisk risks the reliability of + the entire cluster. + </para> + </warning> + <para> To define a tablespace, use the <xref linkend="sql-createtablespace"> command, for example:<indexterm><primary>CREATE TABLESPACE</></>: <programlisting> -CREATE TABLESPACE fastspace LOCATION '/mnt/sda1/postgresql/data'; +CREATE TABLESPACE fastspace LOCATION '/ssd1/postgresql/data'; </programlisting> The location must be an existing, empty directory that is owned by the <productname>PostgreSQL</> operating system user. All objects subsequently created within the tablespace will be stored in files underneath this - directory. + directory. The location must not be on removable or transient storage, + as the cluster might fail to function if the tablespace is missing + or lost. </para> <note> diff --git a/doc/src/sgml/ref/create_tablespace.sgml b/doc/src/sgml/ref/create_tablespace.sgml index b6435650578..cf6215ee608 100644 --- a/doc/src/sgml/ref/create_tablespace.sgml +++ b/doc/src/sgml/ref/create_tablespace.sgml @@ -50,6 +50,14 @@ CREATE TABLESPACE <replaceable class="parameter">tablespace_name</replaceable> <command>CREATE INDEX</> or <command>ADD CONSTRAINT</> to have the data files for these objects stored within the specified tablespace. </para> + + <warning> + <para> + A tablespace cannot be used independently of the cluster in which it + is defined; see <xref linkend="manage-ag-tablespaces"/>. + </para> + </warning> + </refsect1> <refsect1> |