Re: Re: COPY BINARY file format proposal

On Sun, Dec 10, 2000 at 08:51:52PM -0500, Tom Lane wrote:
> ncm@zembu.com (Nathan Myers) writes:
> > I'd like to see a timestamp for when the image was created, and a 
> > 128-byte comment field to allow annotations, even after the fact.
> 
> Both seem like reasonable options.  If you don't mind, however,
> I'd suggest that they be left for inclusion as chunks in the header
> extension area, rather than nailing them down in the fixed header.
> 
> The advantage of handling a comment that way is obvious: it needn't
> be fixed-length.  As for the timestamp, handling it as an optional
> chunk would allow graceful substitution of a different timestamp
> format, which we'll need when 2038 begins to loom.

I don't know if you get the point of the fixed-size comment field.  
The idea was that a comment could be poked into an existing COPY 
image, after it was written.  A variable-size comment field in an
already-written image might leave no space to poke in anything.  A 
variable-size comment field with a required minimum size would 
satisfy both needs, at some cost in complexity.  
> Basically what I want to do at the moment is get a minimal format
> spec nailed down for 7.1.  There'll be time for neat extras later
> as long as we get it right now --- but there's not a lot of time
> for extras before 7.1.

I understand.

Nathan Myers
ncm@zembu.com