Re: tune postgres for UPDATE

On Tue, Dec 9, 2008 at 9:13 PM, Scott Marlowe <scott(dot)marlowe(at)gmail(dot)com>wrote:

>
>
> I'm pretty sure you'd have to vacuum still in between runs or the
> extra fill factor space would only get used the first time. I.e.:
>
> create table fill factor 50%
> load data into table
> update whole table -- 50% free space gets used.
> (should vacuum here but didn't)
> update whole table -- boom, new tuples are added onto the end of the table.
>
>
Not really with 8.3. Assuming there are no long running transactions
covering both the updates, HOT will free up the space used by the old (now
DEAD) tuples and the second update will reuse that, at least for for the
most common cases.

Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB http://www.enterprisedb.com