[Info-vax] The best VMS features, was: Re: openvms renaming file

[Arne Vajhøj]

On 5/28/2018 3:17 PM, seasoned_geek wrote:
> On Monday, May 28, 2018 at 1:31:49 PM UTC-5, Arne Vajhøj wrote:
>> On 5/28/2018 11:01 AM, Dave Froble wrote:
>>>>
>>>> But maybe great for replacing index-sequential files.
>>>
>>> I don't think so.  RMS indexed files allow concurrent use, using the DLM.
>>
>> You are right.
>>
>> SQLite will only replace let us say the low-end of index-sequential
>> files usage.
> 
> That is making the grand assumption that SQLite on VMS wouldn't integrate
> DLM support.

That would be a major rewrite of SQLite. Not realistic.

> Given that any port would most likely use RMS to create its file, it
> could get DLM by default, depending on what type of file.

A SQLite database is number of pages with a page size is between
512 and 64K (same for all pages in a given database).

There are several possible VMS file formats: FIX 512, UDF etc..

And RMS can do locking of like FIX 512 records.

But will an application written based on an assumption about
exclusive file access work with shared access and basic RMS
record/block locking.

I don't think so.

Arne