Обсуждение: Table-space documentation

Поиск
Список
Период
Сортировка

Table-space documentation

От
PG Doc comments form
Дата:
The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/16/manage-ag-tablespaces.html
Description:

While reading the table-space documentation
https://www.postgresql.org/docs/16/manage-ag-tablespaces.html the
information I was looking for was not included.  The page invites feedback,
so I though I would share.  I was specifically looking for information on
maximum table-space size and whether there is a use-case in which you would
create several table-spaces to split your tables / indexes logically.  I am
from an Oracle world and it is normal for me to think about creating
multiple table-spaces for groups of tables and placing a size on the
table-space so that space does not extend and fill the o/s disk-space.  It
would be nice for the documentation to include information about this topic.
 Even if it is says that these factors I should not worry about as postgres
handles them.

Re: Table-space documentation

От
"David G. Johnston"
Дата:
On Sunday, November 26, 2023, PG Doc comments form <noreply@postgresql.org> wrote:
The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/16/manage-ag-tablespaces.html
Description:

While reading the table-space documentation
https://www.postgresql.org/docs/16/manage-ag-tablespaces.html the
information I was looking for was not included.  The page invites feedback,
so I though I would share.  I was specifically looking for information on
maximum table-space size and whether there is a use-case in which you would
create several table-spaces to split your tables / indexes logically.  I am
from an Oracle world and it is normal for me to think about creating
multiple table-spaces for groups of tables and placing a size on the
table-space so that space does not extend and fill the o/s disk-space.  It
would be nice for the documentation to include information about this topic.
 Even if it is says that these factors I should not worry about as postgres
handles them.

We tend to avoid documenting things that don’t exist.  So the lack of a documented limit or any syntax to define one means no limit exists.

As for usage patterns, there is a note I thought (maybe wiki FAQ?) that since the only thing you get with a tablespace is another root level storage place having more than one per disk really serves no purpose.

David J.

Re: Table-space documentation

От
Laurenz Albe
Дата:
On Sun, 2023-11-26 at 21:41 +0000, PG Doc comments form wrote:
> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/16/manage-ag-tablespaces.html
> Description:
>
> While reading the table-space documentation
> https://www.postgresql.org/docs/16/manage-ag-tablespaces.html the
> information I was looking for was not included.  The page invites feedback,
> so I though I would share.  I was specifically looking for information on
> maximum table-space size and whether there is a use-case in which you would
> create several table-spaces to split your tables / indexes logically.  I am
> from an Oracle world and it is normal for me to think about creating
> multiple table-spaces for groups of tables and placing a size on the
> table-space so that space does not extend and fill the o/s disk-space.  It
> would be nice for the documentation to include information about this topic.
>  Even if it is says that these factors I should not worry about as postgres
> handles them.

There is no maximum tablespace size, other than the size of the filesystem
the tablespace is on.

In 99% of all cases, don't create a tablespace in PostgreSQL.  Just use
the default tablespace.

In a virtualized environment, don't ever create a tablespace.

Tablespaces were more important back what people had physical boxes
with physical disks of limited size.

There are still some use cases, but they are extremely rare.

Yours,
Laurenz Albe