Re: Fixed length data types issue - Mailing list pgsql-hackers

From Gregory Stark
Subject Re: Fixed length data types issue
Date
Msg-id 878xkvbu8i.fsf@enterprisedb.com
Whole thread Raw
In response to Re: Fixed length data types issue  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane <tgl@sss.pgh.pa.us> writes:

> Martijn van Oosterhout <kleptog@svana.org> writes:
>> On Thu, Sep 07, 2006 at 11:57:26AM +0100, Gregory Stark wrote:
>>> Just brain storming here. But what happens if we make Datum 2*sizeof(pointer)
>>> and stored the typmod and/or attlen in it?
>
>> The fundamental property of a Datum is that you can pass it by value to
>> a C function. This generally means it has to fit in a register. On the
>> whole, the CPU register size is the same as the pointer size, so
>> 2*sizeof(pointer) is unlikely to fit...
>
> Not to mention the problem that such a change would break every single
> datatype-manipulation function in both the core backend and every
> user-written datatype.  I don't think we're going there.

Sure, I'm just brain storming. Sometimes thinking about outlandish ideas can
result in quiet reasonable ideas appearing down the line.

--  Gregory Stark EnterpriseDB          http://www.enterprisedb.com


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