Thread: Re: [PATCHES] Intervals within information_schema

Greg Sabino Mullane wrote:
> I was looking over the "FIXME" marks within the
> information_schema.sql, and the last ones left (after my previous
> patch) are for interval_type and interval_precision. It looks to me
> as if the standard is differentiating between datetime_precision and
> interval_precision (see attached patch), so I pulled those apart (for
> one view). Does anyone know what is supposed to go into the
> interval_type field?

INTERVAL_TYPE IN
( 'YEAR', 'MONTH', 'DAY', 'HOUR', 'MINUTE', 'SECOND', 'YEAR TO MONTH', 'DAY TO HOUR', 'DAY TO MINUTE', 'DAY TO SECOND',
'HOURTO MINUTE', 'HOUR TO SECOND', 'MINUTE TO SECOND' )
 

Also, depending on which one of these is specified, the precision field 
varies in meaning.  I haven't done a complete analysis, but it might 
not be as simple as your patch suggests.

-- 
Peter Eisentraut
http://developer.postgresql.org/~petere/

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>> Does anyone know what is supposed to go into the interval_type field?

> INTERVAL_TYPE IN
> ( 'YEAR', 'MONTH', 'DAY', 'HOUR', 'MINUTE', 'SECOND',
>   'YEAR TO MONTH', 'DAY TO HOUR', 'DAY TO MINUTE',
>   'DAY TO SECOND', 'HOUR TO MINUTE',
>   'HOUR TO SECOND', 'MINUTE TO SECOND' )
>
> Also, depending on which one of these is specified, the precision field
> varies in meaning.  I haven't done a complete analysis, but it might
> not be as simple as your patch suggests.

Yes, I saw some docs that hinted as much. I'm still not clear on exactly
what interval_type is supposed to represent, or at least how it would ever
apply to a Postgres attribute. It almost seems as though the spec is calling
for interval_type of 'HOURS' and interval_precision of '2' for an example
interval of '2 hours'? I'd normally say that we should leave it as NULL in
such a case, but someone added a "FIXME" at some point, which led me to
ask exactly what should go in there. Not a big deal, I suppose - it looks
as though few, if any, other products are using those fields either.
Thanks for the reply.

- --
Greg Sabino Mullane greg@turnstep.com
End Point Corporation
PGP Key: 0x14964AC8 200608250614
http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8
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