Details of TTable memory usage, Please! 
Author Message
 Details of TTable memory usage, Please!

If I have two separate TTable components pointed at the same Table,
does each TTable load a copy of the data onto memory?  i.e. do I have
two separate copies of the same Table in RAM or do they just POINT to
a single copy managed by the BDE?

I need to know in order to guesstimate RAM requirements and adjust my
implementation accordingly...  obviously it makes a BIG difference!

If any of you Borland folks read this, it would be a really good idea
to document this on the next release. BTW, I commend you guys for
being out here answering questions, it portraits a good corporate
image.

thanks,

-RR



Mon, 16 Mar 1998 03:00:00 GMT  
 Details of TTable memory usage, Please!

Quote:

> A TTable component does not load all the rows from a table into memory. It
> loads as many as are needed for display (more if a multi-record TDBGrid
> component is used than for a set of TDBEdit components) plus a small number
> of rows as a read-ahead buffer. Each new row read will be retrieved with a
> FETCH in background SQL.

> Yes, the record buffer for two TTable components will be independent of
> each other. So, unless you need to move the row pointer independently in
> each, you would make more economical use of memory if you used only one
> TTable component and connected multiple data-aware components to it. This
> also simplifies many situations where the same data set on different forms
> need to be synchronized.

In this case, how does TTable work when there are NO display controls and the procedure is
scanning through the table processing it redcord by record...or is there a more efficient way to
do this?

--
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Russell Weetch
http://www.ukindex.co.uk/
** HAVE YOU REGISTERED YOUR WEB SITE? **
'quite exciting this computer magic'
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*



Tue, 17 Mar 1998 03:00:00 GMT  
 Details of TTable memory usage, Please!

: A TTable component does not load all the rows from a table into memory. It
: loads as many as are needed for display (more if a multi-record TDBGrid
: component is used than for a set of TDBEdit components) plus a small number
: of rows as a read-ahead buffer. Each new row read will be retrieved with a
: FETCH in background SQL.

Does this mean that the BDE builds no data structures in RAM?!  If so, it
seems rather inefficient...   wouldn't it be smart to build a binary search
tree or some other data structure to store the data for searching/sorting,
etc?

I thought you Borland folk didn't include container libraries like the
BC++ BIDS with Delphi because the BDE/components take care of it!

Should I dust-off my own Turbo Pascal data structures?

-RR

PS you guys really need to include this information in the documentation!



Wed, 18 Mar 1998 03:00:00 GMT  
 Details of TTable memory usage, Please!

Quote:


> PS you guys really need to include this information in the documentation!

Yes, I agree. I have the BDE docs (shipped over form the USA at great expense
becuase Borland UK don't stock them!) but it is not enough. Some good solid examples of using
the procs and functions with Delphi would save an awful lot of experimentation
 - it might be fun and challenging but when you are having to develop things for clients speed is
more important.

Perhaps Steve or someone from Borland could provide an Index of the technicasl docs they have in
this area. Which brings me on to another point, getting through to ftp.borland is {*filter*} - how about some
mirror sites?

--
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Russell Weetch
http://www.*-*-*.com/
** HAVE YOU REGISTERED YOUR WEB SITE? **
'quite exciting this computer magic'
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*



Thu, 19 Mar 1998 03:00:00 GMT  
 
 [ 4 post ] 

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