which performance can I explected with DBIsam if I compare that with Paradox (BDE) used as local table. Paradox used only as local table is very
fast (not really stable) but fast. Is DBIsam reach the same performance. Is TTable as derived as a Select or TTable is used the same way than
paradox, as a table.

Francois,

<< which performance can I explected with DBIsam if I compare that with
Paradox (BDE) used as local table. Paradox used only as local table is very
fast (not really stable) but fast. Is DBIsam reach the same performance. Is
TTable as derived as a Select or TTable is used the same way than paradox,
as a table. >>

If you're using Local Share=False with the BDE, then you won't see the same
type of performance with DBISAM that you are with Paradox without opening up
all tables exclusively in DBISAM, which may or may not be possible depending
upon how they are used in the application.   DBISAM assumes that tables will
be shared, whereas the BDE only goes into "sharing" mode when Local
Share=True.

However, having said all that, the query optimizer in DBISAM is fairly good,
and will deliver very good performance in almost all cases with respect to
optimized filters and queries.

--
Tim Young
Elevate Software
www.elevatesoft.com

Hi  Francois,

As Tim has already suggested DBISam is quite comparable with BDE/Paradox
provided you use optimized queries.

With the BDE it didn't matter much with queries if you were querying on
indexed fields or not, but with DBISam there is a huge performance hit (or
increase whichever way you wish to look at it) between optimized and
non-optimized queries.

As for TTables - I don't believe you'll notice a difference in speed at all.
It was the queries where I found the difference (and then, only if the
tables weren't optimized).

I moved from Paradox and the BDE to DBISam a few years ago and have never
looked back. It's very simple to convert the applications over, and DBISam
gives a vaster greater amount of control over the data and files than
Paradox and the BDE could ever hope to achieve.

Cheers

Adam.

My issue with the BDE is that it is deprecated.
If there is a bug, you're dead.
I switched quite a few years ago for a few reasons:

(a) install size much smaller;
(b) encryption in Paradox is AWFUL;

and as noted, dealing with a deprecated engine.

The BDE was great when supported; when all of the people working on it left, no point in
using it- and at the time Interbase cost A LOT.

Herb


You missed out my favourite - BLOB has been modified.

Roy Lambert

Hi Herb,

> (a) install size much smaller;

You mean that you can deploy an application without any external engines
needing to be installed or configured? That was a big plus for me.

> (b) encryption in Paradox is AWFUL;

You mean the encryption that can be bypassed with one 'backdoor' password?


> and as noted, dealing with a deprecated engine.

That caused all sorts of crashes for me when certain printer drivers were
loaded... (strangely enough).

> The BDE was great when supported; when all of the people working on it
> left, no point in
> using it- and at the time Interbase cost A LOT.

I tried interbase before trying DBISam. (And unfortunately wrote an
appliation in Interbase that I later regreted after finding DBISam.)

Plus the COALESCE command...

Plus memory tables....

Plus sooooo many additional SQL commands we didn't have with the BDE.

Plus an easy way to implement data verification and repair in our
applications...

Plus excellent support from Tim, and a great community....

Plus... oh - I guess I better stop there, or I'll start writing a novel.

"Herb (Kraft)"
> My issue with the BDE is that it is deprecated.
> If there is a bug, you're dead.
> I switched quite a few years ago for a few reasons:
>
> (a) install size much smaller;
> (b) encryption in Paradox is AWFUL;
>
> and as noted, dealing with a deprecated engine.
>
> The BDE was great when supported; when all of the people working on it
> left, no point in
> using it- and at the time Interbase cost A LOT.
>

Paradox served me for years but its age is over. Windows XP was the last
Windows version which could handle Paradox properly. All other versions
starting with 2003 server have severe compatibility issues. In Vista, it is
almost impossible to deploy it with an automatic installer and you need lots
of manual hacks to make it run. Again, there is no guarantee that it will
run properly under Vista.