Intervals within information_schema

Started by Greg Sabino Mullaneover 19 years ago3 messageshackers
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#1Greg Sabino Mullane
greg@turnstep.com

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?

Thanks,
--
Greg Sabino Mullane greg@turnstep.com
End Point Corporation
PGP Key: 0x14964AC8 200608241454
http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8

Attachments:

interval_precision.patchtext/x-patch; charset=ISO-8859-1; name=interval_precision.patchDownload+13-7
#2Peter Eisentraut
peter_e@gmx.net
In reply to: Greg Sabino Mullane (#1)
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', '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.

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

#3Greg Sabino Mullane
greg@turnstep.com
In reply to: Peter Eisentraut (#2)
Re: [PATCHES] Intervals within information_schema

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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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