Re: pg_dump locking info

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.

--
Thom Brown
Registered Linux user: #516935