[V4RB] 1.x Open() Delay in Win32

[Ruslan Zasukhin]

On 4/6/06 6:35 PM, "Russ Tyndall" <fitzbew at nc.rr.com> wrote:

Hi Russ,

> I did some more research on this (have to reboot to get back into "slow"
> state), and also poked around on the 'Net to make sure I am interpreting the
> Task Manager readings correctly.
> 
> In Win XP Home (SP2), 2.5ghz Celeron D with 512 mb of physical RAM, it takes
> 24 wall-clock seconds for V4RB 1.x to open a 155mb encrypted database the
> *first* time after a startup/reboot of the PC.  Subsequent openings are very
> speedy.
> 
> The amount of memory used on the PC increases by only 3mb during the Open()
> call.  This is true during each Open(), not just the first. So, I do not
> think the delay is due to the OS caching the database. (System cache and
> Kernel memory hardly change at all.)
> 
> The first time the DB is opened, this 3mb of memory is consumed very slowly
> during the 24 secs.  On subsequent openings, this 3mb is consumed quickly.

Actually we have see that on some not-clear reason Windwows XP do much
slower flushed of HDD then do MAC OS X using practically the same HDD
hardware. 

We have se this effect about 3-4 years ago also.
 
The reason open takes so long time in your case is that you have in db a
lots of VarChar and index files. When Valentina 1.x open such PAGE-Files it
needs read their header. So this cause many random access to HDD. And this
not require a lots of RAM as you see.

> My (virtual) Win98se PC with 128mb of RAM does not hesitate at all during
> Open().

Sounds like Win98 was faster of XP on random access.
 
> Even more disappointing, Vstudio suffers this slowdown also when opening an
> unencrypted converted version of the same 155mb database so I don't think
> migrating to 2.x will help with this. It also rules out a Realbasic cause.
> (Also, that would seem to rule out a problem relating to the encryption.)

I have not catch. Valentina Studio open your 1.x daatbase. Right ?
But this means that 1.x engine is used.

To see work of 2.x engine, you need do Convert_1_2 of your db into 2.x
format. Then open this new 2.x database using Valentina Studio. Then only
will work 2.x engine.
 
> The delay *does* appear to be related to db size.  I experimented with a
> trimmed down version of the db (28mb), and it opened quickly every time.
> Also interesting, the Open() call on this smaller db does not cause *any*
> noticeable memory to be consumed.

Hmm. What cache size you use then ?
Try set it bigger 
 
> I have another 388mb db that uses an alternative engine that opens swiftly
> *every* time on the same machine.
> 
> I'm quite puzzled about what to do here, but I don't think any of us would
> expect either 1.x or 2.x to take so long to simply open a 100-200mb db.

Agree. 

We was going make lazy access to header of PageFiles to not do this on open.

-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]