[Info-vax] Empty blocks in FILES-11 directory files.

[Bob Gezelter]

On Sunday, September 25, 2022 at 1:59:55 PM UTC-4, osuv... at gmail.com wrote:
> On Sunday, September 25, 2022 at 10:27:19 AM UTC-4, Volker Halle wrote: 
> > Please read the second half of that sentence: I strongly believe you can't do a window turn (which involves the XQP), if you are already in the XQP executing a directory operation. So directory files must be contiguous. 
> >
> There is a middle ground, such as what happens with the pager. The page file doesn't have to be contiguous, 
> but the file can't have extension headers (i.e. all retrieval pointers must fit in the primary header). If the header 
> for the directory file is cached in memory, a window turn won't require I/O.
Mark,

Am in a bit of a hurry, so I will not go into details.

However, COPY is definitely not needed. RENAME is quite enough, preferably in the advantageous order to not create repeated shuffles. 

I would have to go digging, but it is also advantageous to create a directory of the desired size, and not just use the default. That way, there is no need to grow the directory and incur the resulting copies.

- Bob Gezelter, http://www.rlgsc.com