Re: Adding TEXT columns tanks performance?

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On 02/08/07 20:50, Arturo Perez wrote:
> Hi all,
>
> Saturday I changed a table to add a varchar(24) and a TEXT column.  It's
> used for some reporting purposes (small potatoe stuff really) and the
> TEXT column remains mostly empty.  However, this week performance has
> gotten terrible.  Queries joining against the aforementioned table have
> gone from 40s to 1500s.  The schema change is the only explanation I
> have for the 30x slower queries.  The queries have definitely gotten
> disk-bound (I can see the connection process sitting in the D state for
> several minutes).
>
> This is pg8.1.4 on Linux RedHat. Would adding a TEXT column impact
> things that much?  The change to the schema was
>
> alter table foo add column title text;

Could the issue be record fragmentation?  Does PG even suffer from
record fragmentation?

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