Re: [HACKERS] generic LONG VARLENA

wieck(at)debis(dot)com (Jan Wieck) writes:
> Tom Lane wrote:
>> Per-type control doesn't strike me as interesting or useful.

> Isn't intended to be a runtime configuration. Just a
> temporary feature to restrict the attributes that can be
> moved off to those types, where WE know that the adt
> functions are prepared for them.

Oh, I see. Yeah, if we wanted to make an interim release where only
some datatypes were ready for long values, that would be a necessary
safety measure. But I'd rather plan on just getting it done in one
release.

>> BTW, it strikes me we should drop the "lztext" special datatype, and
>> instead have compression automatically applied to any varlena that
>> we are contemplating putting out-of-line. (If we're really lucky,
>> that saves us having to put the value out-of-line!)

> Nice idea, and should be technically easy since the
> compressor itself is separated from the lztext type. OTOH the
> user then will have no choice to prevent compression tries
> for performance reasons.
> So this feature again is something that IMHO should go into a
> configurable option.

Good point. You're right, there should be a per-datatype "don't
bother to try to compress this type" flag. (Is per-datatype the
right granularity?)

regards, tom lane