Re: pg_dumpall

>Alvaro Herrera <alvherre(at)commandprompt(dot)com> wrote:
> Glyn Astill wrote:
> > Out of interest, how does pg_dump manage to do a snapshot of a
> > database at an instant in time?
> >
> > My mental picture of pg_dump was just a series of queries dumping
> out
> > the tables...
>
> begin;
> set transaction isolation level serializable;
>
> --- begin dumping stuff;
>

Wouldn't that just lock everything so nothing could be updated? Or
just the table it is outputting?

I'm guessing I need to go off and school myself on different
isolation levels etc to understand, but say I have 2 tables "sales"
and "sold", and users are selling items with inserts into the sales
table and a count updating manually in sold. Wouldn't these end up
inconsistant in the dump?

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