diff --git a/doc/src/sgml/manage-ag.sgml b/doc/src/sgml/manage-ag.sgml index f1f64634fb95b745b96526a320c93c38c4b5619d..5db8e939e4d86202c773c877f7579e16788f6301 100644 --- a/doc/src/sgml/manage-ag.sgml +++ b/doc/src/sgml/manage-ag.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/manage-ag.sgml,v 2.34 2004/09/30 02:40:23 neilc Exp $ +$PostgreSQL: pgsql/doc/src/sgml/manage-ag.sgml,v 2.35 2004/10/29 02:11:18 neilc Exp $ --> <chapter id="managing-databases"> @@ -347,21 +347,22 @@ dropdb <replaceable class="parameter">dbname</replaceable> </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> @@ -377,14 +378,14 @@ CREATE TABLESPACE fastspace LOCATION '/mnt/sda1/postgresql/data'; </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> @@ -416,17 +417,17 @@ CREATE TABLE foo(i int) TABLESPACE space1; </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>