Re: Schedule decision

• To: netcdf-hdf@xxxxxxxxxxxxxxxx
• Subject: Re: Schedule decision
• From: Ed Hartnett <ed@xxxxxxxxxxxxxxxx>
• Date: Thu, 21 Apr 2005 04:10:18 -0600

Quincey Koziol <koziol@xxxxxxxxxxxxx> writes:

> Hi Mike,
>
>> This question came up today at the NASA briefing, when we were talking 
>> about the netCDF 4 project.  There was a weak but immediate and negative 
>> reaction to using time as a proxy for creation order.  The reason given was 
>> that many applications would want to use the creation time as an attribute, 
>> but that the times used would not necessarily give the same ordering as 
>> creation time because different times might be relative to different time 
>> zones.  I have a feeling there were other cases, given the reaction people 
>> had.
>> 
>> Of course this could only happen if people were allowed to change the 
>> "creation time."  And one could also argue that creation time is a 
>> different attribute -- it's the time the link was created, not the time the 
>> data was collected.  But I have a feeling this would just lead to confusion.
>> 
>> So at best, I think there is concern that this could led to confusion.  I 
>> tend to agree.
>
>     Ok, I think we've heard enough customer push-back on this that we ought to
> provide both options and allow people to choose which they'd like.  Here's a
> list of the fields that I'm planning on storing on storing for each link:
>     - Name (indexable, must be unique, modifiable)
>     - Creation time (indexable, may be non-unique, modifiable)
>     - Creation order (indexable, unique, monotonicly increasing, 
> non-modifiable)
>     - Character set (i.e. ASCII, UTF-8, etc.) (non-indexable?, non-unique,
>         modifiable)
>     - Object address/link target (for hard/soft links) (non-indexable, may be
>         non-unique (for multiple links to same object), modifiable?)
>
>     Applications can determine which of the three indexable fields they'd like
> to have an index maintained for with a group creation property.  They will
> choose an index for iteration, etc. with a group access property.
>
>     Quincey

Thanks Quincey!

I think that will work better for netCDF-4.

Ed
-- 
Ed Hartnett  -- ed@xxxxxxxxxxxxxxxx

• Follow-Ups:
  • Re: Schedule decision
    • From: Robert E. McGrath

• References:
  • Re: Schedule decision
    • From: Quincey Koziol