On Mon, Sep 19, 2011 at 7:53 PM, Stephen Frost <sfrost@snowman.net> wrote:
> Igor,
>
> * Igor Chudov (ichudov@gmail.com) wrote:
>> Would the time that it takes, differ a great deal, depending on whether the
>> table has only 100,000 or 5,000,000 records?
>
> Yes, because PostgreSQL is going to copy the data. If you don't need or
> want it to be copied, just use a view. I've never heard of any
> relational database implementing 'copy on write' type semantics, if
> that's what you're asking about. Databases, unlike applications with
> code in memory that's constantly copied, are typically focused around
> minimizing duplication of data (since it all has to end up on disk at
> some point). Not much point in having the overhead of COW for that kind
> of environment, I wouldn't think.
Isn't the WAL basically COW?
--
Jon
