Re: Running update in chunks? - Mailing list pgsql-general

From Jasen Betts
Subject Re: Running update in chunks?
Date
Msg-id ke2u3p$oue$1@gonzo.reversiblemaps.ath.cx
Whole thread Raw
In response to Re: Running update in chunks?  ("Kevin Grittner" <kgrittn@mail.com>)
List pgsql-general
On 2013-01-25, Tim Uckun <timuckun@gmail.com> wrote:
>> I agree that seems like the most likely cause. Each update to the
>> row holding the hstore column requires adding new index entries for
>> all the hstore elements, and autovacuum will need to clean up the
>> old ones in the background. The best solution would be to either
>> normalize the data instead of using hstore, or move the hstore to a
>> separate table which is referenced by some sort of ID from the
>> frequently-updated table.
>
>
> That's very interesting. I can certainly split up the table, no big
> deal there.  So would the index be redone even if I am not updating
> the hstore field itself?

Absolutely! see MVCC.

 http://www.postgresql.org/docs/current/static/mvcc-intro.html


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