Re: Domains versus arrays versus typmods

On Wed, Oct 20, 2010 at 10:03 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> On Tue, Oct 19, 2010 at 9:17 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>> We've already accepted the cost of doing getBaseTypeAndTypmod() in a
>>> whole lot of performance-critical parsing paths, on the off chance that
>>> the target datatype might be a domain.  It's not apparent to me that
>>> array subscripting is so important as to deserve an exemption from that.
>>> Especially when not doing so doesn't work.
>
>> Hmm... so are there no cases where zeroing out the typelem will cost
>> us an otherwise-unnecessary syscache lookup?
>
> My point is that anyplace that is relying on the surface typelem,
> without drilling down to see what the base type is, is wrong.
> So yeah, those lookups are (will be) necessary.

OK.  In that case, +1 from me.

--
Robert Haas
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