What is error -61?

[Ruslan Zasukhin]

on 1/21/04 9:45 AM, Francois Van Lerberghe at fvanlerberghe at freegates.be
wrote:

> le 19/01/04 18:46, Keith DeLong <delong at redcort.com> a écrit :
> 
>>>   -61   wrPermErr  Write permissions error; Not a publisher
>> 
>> 
>> In V4RB under OS X -61 means you just tried to write to a V4RB database that
>> someone else opened before you (or it was left open by a previous crash).
> 
> I'm not sure to understand completely what's happening.
> If MacOS X allow multiple writer and don't provide exclusive lock (as
> described in the TN), why can we get an error -61 ?

In MacOS X we will not get it.

You an easy reproduce.

Make COPY of VAPP or your projector.
Run both copies, from each copy open some db.

They open it.

Real Problem come when both apps will try write something into the same db.
This operation can corrupt db.



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Please note:

    Valentina was NEVER positioned as db
    that can do shared access to db files.

Shared Access, as you know -- is old way which was used BEFORE client/server
technologies was born.

Shared Access is very slow and not effective.
-- we cannot have real cache
-- when you open db from other computer, and do e.g. Search then
    indexes are loaded into RAM of your computer. => big network traffic.


We are not going patch Valentina to support shared access,
Mainly because this must be made on kernel level and require MORE operations
calls to file system, which can slow down overall speed of kernel.


-- 
Best regards,
Ruslan Zasukhin      [ I feel the need...the need for speed ]
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e-mail: ruslan at paradigmasoft.com
web: http://www.paradigmasoft.com

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