Re: pg_dump locking info

On 15 August 2010 10:38, Thom Brown <thom(at)linux(dot)com> wrote:
> On 15 August 2010 10:29, Thom Brown <thom(at)linux(dot)com> wrote:
>> On 15 August 2010 10:01, Thom Brown <thom(at)linux(dot)com> wrote:
>>> Is this right?  I'm looking at
>>> http://www.postgresql.org/docs/current/static/backup-dump.html
>>>
>>> It says, "pg_dump does not block other operations on the database
>>> while it is working. (Exceptions are those operations that need to
>>> operate with an exclusive lock, such as most forms of ALTER TABLE.)"
>>>
>>> So pg_dump actually performs an ALTER TABLE sometimes? :S
>>>
>>
>> And whilst I was perusing the docs, I also noticed this on
>> http://www.postgresql.org/docs/current/static/backup.html
>>
>> "Each has its own strengths and weaknesses. Each is discussed in turn below."
>>
>> That sentence is at the bottom of the page.  It would make sense in a
>> PDF, but might be a confusing in section-by-section HTML
>> documentation.
>>
>
> Another thing I noticed, going back to
> http://www.postgresql.org/docs/current/static/backup-file.html , is
> that it makes no mention of the fact that file system level backups
> are useless if being used to restore in a different major version.
> Maybe "There are two restrictions, however, which make this method
> impractical, or at least inferior to the pg_dump method" should be
> changed to "There are three..." and add the point that
> pg_dump/pg_dumpall is mostly immune to such limitations.
>

In the docs for version 9.0, I think the following from
http://www.postgresql.org/docs/9.0/static/migration.html should be
updated to make mention of streaming replication:

"It is also possible to use replication methods, such as Slony, to
create a standby server with the updated version of PostgreSQL."

Of course, this page doesn't make any mention of pg_upgrade for
upgrading from 8.3+ and probably should.
--
Thom Brown
Registered Linux user: #516935