Re: Effect of large text field data on queries

Tom Lane wrote:
> Glen Parker <glenebob@nwlink.com> writes:
>> Why would very large text values effect the speed of a seq scan that
>> does not actually evaluate those values?
>
> I'd actually suppose it's the smaller values (up to a few hundred bytes)
> that impact this the most.  Really wide fields would be pushed
> out-of-line.

Meaning that the portion of the text value stored in the companion TOAST
table would be ignored for this type of query, correct?  That's why I'm
concerned.

How much of a TOAST'd field is actually stored in the main heap table?
Is there a way to configure that amount?


-Glen