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Thread What are the Cached Updates ( in edb 2.03 ) ?
Thu, Oct 16 2008 10:42 AMPermanent Link

"Mauro Botta"
What are the Cached Updates ( in edb 2.03 ) ?

how work ?

Thu, Oct 16 2008 1:43 PMPermanent Link

Heiko Knuettel
Something like that :

http://www.elevatesoft.com/manual?action=mancompmethod&id=dbisam4&product=r&version=2007&comp=TDBISAMDataSet&method=BeginCachedUpdates
http://www.elevatesoft.com/manual?action=mancompmethod&id=dbisam4&product=r&version=2007&comp=TDBISAMDataSet&method=ApplyCachedUpdates

and to be honestly, I fail to see a scenario where one absolutely needs them. But there
seem to be people out there waiting desperately for them, maybe they can explain better.

Heiko
Thu, Oct 16 2008 4:19 PMPermanent Link

Tim Young [Elevate Software]

Elevate Software, Inc.

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Email timyoung@elevatesoft.com

Heiko,

<< and to be honestly, I fail to see a scenario where one absolutely needs
them. But there seem to be people out there waiting desperately for them,
maybe they can explain better. >>

They're helpful when you want to effectively do a buffered update of the
detail side of a one-to-many linkage.  It allows you to treat an entire set
of rows as a single update, and to hide any interim updates from showing up
until the application of the updates takes place.

--
Tim Young
Elevate Software
www.elevatesoft.com

Thu, Oct 16 2008 6:51 PMPermanent Link

Heiko Knuettel
Tim,

Thanks for the explanation. Sounds to me like a situation, where I would use

dataset.DisableControls
database.StartTransaction
dataset.Edit...Post...Edit...Post...
database.Commit
dataset.EnableControls
grid.Refresh

?

But since they are not ready, it can't be that bad that I never used them... Smiley

Heiko
Thu, Oct 16 2008 9:17 PMPermanent Link

Charalabos Michael
Tim,

> Heiko,
>
> << and to be honestly, I fail to see a scenario where one absolutely needs
> them. But there seem to be people out there waiting desperately for them,
> maybe they can explain better. >>
>
> They're helpful when you want to effectively do a buffered update of the
> detail side of a one-to-many linkage.  It allows you to treat an entire set
> of rows as a single update, and to hide any interim updates from showing up
> until the application of the updates takes place.
>

Which it also helps very much to cancel all data in master & details
tables very easily!

--
Charalabos Michael - [Creation Power] - http://www.creationpower.gr
Thu, Oct 16 2008 9:34 PMPermanent Link

"Jeff Cook"
Heiko Knuettel wrote:

> Tim,
>
> Thanks for the explanation. Sounds to me like a situation, where I
> would use
>
> dataset.DisableControls
> database.StartTransaction
> dataset.Edit...Post...Edit...Post...
> database.Commit
> dataset.EnableControls
> grid.Refresh
>
> ?
>
> But since they are not ready, it can't be that bad that I never used
> them... Smiley
>
> Heiko

Kia Orana Heiko

I think ... but don't know for sure as I also haven't used them ...
that you would use them where there was some user interaction in the
Edit...Post...Edit..Post.  In that case it would hold up the whole
system if you did it in a transaction.  Personally, I've used memory
tables in DBISAM to do this sort of thing which is why I haven't used
cached updates.

Kia Manuia

Jeff

--
Jeff Cook
Aspect Systems Ltd
www.aspect.co.nz
+
Joan and Jeff Cook
The Cooks Oasis
www.cookislandsoasis.com
Fri, Oct 17 2008 3:53 AMPermanent Link

Charalabos Michael
Dear Jeff,

> I think ... but don't know for sure as I also haven't used them ...
> that you would use them where there was some user interaction in the
> Edit...Post...Edit..Post.  In that case it would hold up the whole
> system if you did it in a transaction.  Personally, I've used memory
> tables in DBISAM to do this sort of thing which is why I haven't used
> cached updates.
>
> Kia Manuia
>
> Jeff

Well, cached updates makes the same thing as you do without locking the
tables.

--
Charalabos Michael - [Creation Power] - http://www.creationpower.gr
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