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<chapter id="managing-databases">
</para>
<para>
- By using tablespaces, a database administrator can control the disk
- layout of a <productname>PostgreSQL</> installation. This is useful in
- at least two ways. Firstly, if the partition or volume on which the cluster
- was initialized runs out of space and cannot be extended logically
- or otherwise, a tablespace can be created on a different partition
- and used until the system can be reconfigured.
+ By using tablespaces, an administrator can control the disk layout
+ of a <productname>PostgreSQL</> installation. This is useful in at
+ least two ways. First, if the partition or volume on which the
+ cluster was initialized runs out of space and cannot be extended,
+ a tablespace can be created on a different partition and used
+ until the system can be reconfigured.
</para>
<para>
- Secondly, tablespaces allow a database administrator to arrange data
- locations based on the usage patterns of database objects. For
- example, an index which is very heavily used can be placed on very fast,
- highly available disk, such as an expensive solid state device. At the same
- time a table storing archived data which is rarely used or not performance
- critical could be stored on a less expensive, slower disk system.
+ Second, tablespaces allow an administrator to use knowledge of the
+ usage pattern of database objects to optimize performance. For
+ example, an index which is very heavily used can be placed on a
+ very fast, highly available disk, such as an expensive solid state
+ device. At the same time a table storing archived data which is
+ rarely used or not performance critical could be stored on a less
+ expensive, slower disk system.
</para>
<para>
</para>
<note>
- <para>
- There is usually not much point in making more than one
- tablespace per logical filesystem, since you can't control the location
- of individual files within a logical filesystem. However,
- <productname>PostgreSQL</> does not enforce any such limitation, and
- indeed it's not directly aware of the filesystem boundaries on your
- system. It just stores files in the directories you tell it to use.
- </para>
+ <para>
+ There is usually not much point in making more than one
+ tablespace per logical filesystem, since you cannot control the location
+ of individual files within a logical filesystem. However,
+ <productname>PostgreSQL</> does not enforce any such limitation, and
+ indeed it is not directly aware of the filesystem boundaries on your
+ system. It just stores files in the directories you tell it to use.
+ </para>
</note>
<para>
</para>
<para>
- A schema does not in itself occupy any storage (other than a system
- catalog entry), so assigning a tablespace to a schema does not in itself
- do anything. What this actually does is to set a default tablespace
- for tables later created within the schema. If
+ A schema does not in itself occupy any storage (other than a
+ system catalog entry), so assigning a schema to a tablespace does
+ not in itself do anything. What this actually does is to set a
+ default tablespace for tables later created within the schema. If
no tablespace is mentioned when creating a schema, it inherits its
default tablespace from the current database.
</para>
<para>
- The default choice of tablespace for an index is the same tablespace
- already assigned to the table the index is for.
+ The default tablespace for an index is the tablespace associated
+ with the table the index is on.
</para>
<para>