Programming a database, any info? 
Author Message
 Programming a database, any info?

Hello all!!

I'm a delphi 4 programmer and am in the process of creating a BDE
replacement engine. I would like to know of any sites where I can get
ANY info of the following :

1) Database design/programming tips.
2) The latest in database performance/storage theories, optimizations,
etc..
2) Algorithms used for storing records.
3) Algorithms used for indexes.
4) How to create a BDE replacement such that I can use my engine in
place of the BDE and possibly retain use of the data aware components
that Delphi supplies? In other words, I want people to be able to use
the data aware components with it such as TDBGrid, TDBMemo, TDBEdit,
etc...

The info I need would pertain to creating a small to medium databases,
not the Interbase, Oracle or Sybase type of monstrous databases.

ANY help would be MUCH appreciated, even if it's some source code, an
article, a link to a web page, a good DB book, etc...

Thanks a lot!! :-)

Anthony Ortiz



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
<<Anthony Paul Cavalcanti Ortiz:
I'm a Delphi 4 programmer and am in the process of creating a BDE
replacement engine. I would like to know of any sites where I can get
ANY info of the following :

1) Database design/programming tips.
Well, concider this posting a database design tip in the Delphi/VCL context.

<<
2) The latest in database performance/storage theories, optimizations, etc..
2) Algorithms used for storing records.
3) Algorithms used for indexes.
I really believe that the best reason for creating a BDE replacement including a database engine
would be to achieve a behaviour different from the BDE. If you want a square, traditional
cursor-based relational database, it's just not worth the time creating another one. Personally, I
would never use a shareware db-engine unless I needed something different from the regular ones.
I've been checking out a few of them, and I haven't found a good one yet. OK, the BDE isn't
brilliant, but it is not a disaster compared to the rest of the world of traditional databases.

The choice of a DB engine is an Important one, because all concepts are full of compromises, trading
speed for security, fast read/write for disk space & memory, or the other way around. I suggest that
you study one small file-based database and one SQL-server to make a decision about what level of
functionality you want, and study the DBTABLES.PAS unit and the BDE32.HLP to see how things are done
on the application side.

<<
4) How to create a BDE replacement such that I can use my engine in
place of the BDE and possibly retain use of the data aware components
that Delphi supplies? In other words, I want people to be able to use
the data aware components with it such as TDBGrid, TDBMemo, TDBEdit,
etc...

This locks you to creating a cursor-based database, because the interface for the DB-controls are
designed for such. In short - create an equivalent to most parts of the BDE API, and create a
modified DBTABLES unit (renamed, of course).

<<The info I need would pertain to creating a small to medium databases,
not the Interbase, Oracle or Sybase type of monstrous databases.>>

On my 233MHz Laptop I run Oracle server on NT Workstation 4.0 starting the NT Server and Oracle.
Startup takes about 2 minutes. On my 3.2 Gb HDD I have 2 small company databases, MS Office, an
additional Win95, 4 Delphi versions and a lot of projects. I don't quite understand what is
monstrous about that size ? MS Word uses more RAM than Oracle, and Delphi takes longer to load. The
only monstrous about those is the price...

I believe you would have quite a job outperforming Paradox or Oracle.

IMHO, the most important feature missing in network-enabled databases from Paradox to oracle is that
they don't provide a messaging service to notify other users when data changes in the database. If
you implement this functionality, even I would concider taking a look at such a concept..

<<ANY help would be MUCH appreciated, even if it's some source code, an
article, a link to a web page, a good DB book, etc...>>

The book "Using Delphi 3" by Miller, Powell, et al. described how to create a custom dataset with
Delphi.

I'm afraid this was almost 100% discouraging. OK, it might be fun creating a datbase engine. It's a
hell of a lot of work, and you'll learn a lot. But I don't see how these efforts could ever pay off
unless you really need something different from the traditional Relational DB's.

Good luck, anyway !
--

Bjoerge



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
What I dont understand is that why database systems must be so complexe
and difficult. What shall a database do? It should store data! But if
you use the BDE you need thousends of dlls. Why? Could this not be
easier done? Look at Delphi. To access a database you need a TTable, a
TDataSet and special database controls. And all this just to use "a few"
datasets. But then the people are wondering when the exe file is as
large as a 10 gb hd ;) and when the app doesnt work just because a dll
is missing ;). I certainly know that Oracle, Paradox & co. have been
established as standard. But I think a new small&simple database
solution would help developers worldwide enormously.

Alex

Quote:

> <<Anthony Paul Cavalcanti Ortiz:
> I'm a Delphi 4 programmer and am in the process of creating a BDE
> replacement engine. I would like to know of any sites where I can get
> ANY info of the following :

> 1) Database design/programming tips.

> Well, concider this posting a database design tip in the Delphi/VCL context.

> <<
> 2) The latest in database performance/storage theories, optimizations, etc..
> 2) Algorithms used for storing records.
> 3) Algorithms used for indexes.

> I really believe that the best reason for creating a BDE replacement including a database engine
> would be to achieve a behaviour different from the BDE. If you want a square, traditional
> cursor-based relational database, it's just not worth the time creating another one. Personally, I
> would never use a shareware db-engine unless I needed something different from the regular ones.
> I've been checking out a few of them, and I haven't found a good one yet. OK, the BDE isn't
> brilliant, but it is not a disaster compared to the rest of the world of traditional databases.

> The choice of a DB engine is an Important one, because all concepts are full of compromises, trading
> speed for security, fast read/write for disk space & memory, or the other way around. I suggest that
> you study one small file-based database and one SQL-server to make a decision about what level of
> functionality you want, and study the DBTABLES.PAS unit and the BDE32.HLP to see how things are done
> on the application side.

> <<
> 4) How to create a BDE replacement such that I can use my engine in
> place of the BDE and possibly retain use of the data aware components
> that Delphi supplies? In other words, I want people to be able to use
> the data aware components with it such as TDBGrid, TDBMemo, TDBEdit,
> etc...

> This locks you to creating a cursor-based database, because the interface for the DB-controls are
> designed for such. In short - create an equivalent to most parts of the BDE API, and create a
> modified DBTABLES unit (renamed, of course).

> <<The info I need would pertain to creating a small to medium databases,
> not the Interbase, Oracle or Sybase type of monstrous databases.>>

> On my 233MHz Laptop I run Oracle server on NT Workstation 4.0 starting the NT Server and Oracle.
> Startup takes about 2 minutes. On my 3.2 Gb HDD I have 2 small company databases, MS Office, an
> additional Win95, 4 Delphi versions and a lot of projects. I don't quite understand what is
> monstrous about that size ? MS Word uses more RAM than Oracle, and Delphi takes longer to load. The
> only monstrous about those is the price...

> I believe you would have quite a job outperforming Paradox or Oracle.

> IMHO, the most important feature missing in network-enabled databases from Paradox to oracle is that
> they don't provide a messaging service to notify other users when data changes in the database. If
> you implement this functionality, even I would concider taking a look at such a concept..

> <<ANY help would be MUCH appreciated, even if it's some source code, an
> article, a link to a web page, a good DB book, etc...>>

> The book "Using Delphi 3" by Miller, Powell, et al. described how to create a custom dataset with
> Delphi.

> I'm afraid this was almost 100% discouraging. OK, it might be fun creating a datbase engine. It's a
> hell of a lot of work, and you'll learn a lot. But I don't see how these efforts could ever pay off
> unless you really need something different from the traditional Relational DB's.

> Good luck, anyway !
> --

> Bjoerge



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
There are a number of good small databases around and if you don't need the
functionality of the BDE then use one of them. However, there are some very
good reasons why the BDE is the size it is and it does a reasonably good job
at what it was designed to do. The BDE isn't really a database, rather it is
an interface to a number of different databases. In that respect it is more
like ODBC than dBase. For that reason, and that reason alone, it is more
complex than dBase or Paradox by themselves.

This is not to say that a comercial quality database is a simple thing to
implement. If it needs to handle tables up into the 1,000K record count,
multiple concurrent users, multi-segment ascending and descending indexes,
and rich data types a database is by the nature of the problem going to have
to have a fairly high degree of sophistication and, alas, complexity.

What irks me the most are complaints about the size of the BDE. People seem
to think nothing of installing a 250 MB office suite, or 300 MB game. Asking
for 15 MB for data management is considered a crime? Come to think of it, I
haven't read any rants about the size of Delphi itself. Surely those that
think the BDE is too big and bloated must think that a Pascal compiler that
weighs in at 80+ MB is a little over the top ;).


Quote:
> What I dont understand is that why database systems must be so complexe
> and difficult. What shall a database do? It should store data! But if
> you use the BDE you need thousends of dlls. Why? Could this not be
> easier done? Look at Delphi. To access a database you need a TTable, a
> TDataSet and special database controls. And all this just to use "a few"
> datasets. But then the people are wondering when the exe file is as
> large as a 10 gb hd ;) and when the app doesnt work just because a dll
> is missing ;). I certainly know that Oracle, Paradox & co. have been
> established as standard. But I think a new small&simple database
> solution would help developers worldwide enormously.

> Alex


> > <<Anthony Paul Cavalcanti Ortiz:
> > I'm a Delphi 4 programmer and am in the process of creating a BDE
> > replacement engine. I would like to know of any sites where I can get
> > ANY info of the following :

> > 1) Database design/programming tips.

> > Well, concider this posting a database design tip in the Delphi/VCL
context.

> > <<
> > 2) The latest in database performance/storage theories, optimizations,
etc..
> > 2) Algorithms used for storing records.
> > 3) Algorithms used for indexes.

> > I really believe that the best reason for creating a BDE replacement

including a database engine
Quote:
> > would be to achieve a behaviour different from the BDE. If you want a
square, traditional
> > cursor-based relational database, it's just not worth the time creating

another one. Personally, I
Quote:
> > would never use a shareware db-engine unless I needed something

different from the regular ones.
Quote:
> > I've been checking out a few of them, and I haven't found a good one

yet. OK, the BDE isn't
Quote:
> > brilliant, but it is not a disaster compared to the rest of the world of

traditional databases.
Quote:

> > The choice of a DB engine is an Important one, because all concepts are

full of compromises, trading
Quote:
> > speed for security, fast read/write for disk space & memory, or the

other way around. I suggest that
Quote:
> > you study one small file-based database and one SQL-server to make a

decision about what level of
Quote:
> > functionality you want, and study the DBTABLES.PAS unit and the

BDE32.HLP to see how things are done
Quote:
> > on the application side.

> > <<
> > 4) How to create a BDE replacement such that I can use my engine in
> > place of the BDE and possibly retain use of the data aware components
> > that Delphi supplies? In other words, I want people to be able to use
> > the data aware components with it such as TDBGrid, TDBMemo, TDBEdit,
> > etc...

> > This locks you to creating a cursor-based database, because the

interface for the DB-controls are
Quote:
> > designed for such. In short - create an equivalent to most parts of the

BDE API, and create a
Quote:
> > modified DBTABLES unit (renamed, of course).

> > <<The info I need would pertain to creating a small to medium databases,
> > not the Interbase, Oracle or Sybase type of monstrous databases.>>

> > On my 233MHz Laptop I run Oracle server on NT Workstation 4.0 starting

the NT Server and Oracle.
Quote:
> > Startup takes about 2 minutes. On my 3.2 Gb HDD I have 2 small company

databases, MS Office, an
Quote:
> > additional Win95, 4 Delphi versions and a lot of projects. I don't quite
understand what is
> > monstrous about that size ? MS Word uses more RAM than Oracle, and

Delphi takes longer to load. The
Quote:
> > only monstrous about those is the price...

> > I believe you would have quite a job outperforming Paradox or Oracle.

> > IMHO, the most important feature missing in network-enabled databases

from Paradox to oracle is that
Quote:
> > they don't provide a messaging service to notify other users when data

changes in the database. If
Quote:
> > you implement this functionality, even I would concider taking a look at
such a concept..

> > <<ANY help would be MUCH appreciated, even if it's some source code, an
> > article, a link to a web page, a good DB book, etc...>>

> > The book "Using Delphi 3" by Miller, Powell, et al. described how to

create a custom dataset with
Quote:
> > Delphi.

> > I'm afraid this was almost 100% discouraging. OK, it might be fun

creating a datbase engine. It's a
Quote:
> > hell of a lot of work, and you'll learn a lot. But I don't see how these

efforts could ever pay off

- Show quoted text -

Quote:
> > unless you really need something different from the traditional
Relational DB's.

> > Good luck, anyway !
> > --

> > Bjoerge



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
<<Alexander Mueller:
What I dont understand is that why database systems must be so complexe
and difficult. What shall a database do? It should store data!
In the simplest fashion, yes. If you go 10 years back in pascal programming, most apps using what
you would call a database would store their data in native format. It is quite a piece of work
writing this, so it's no surprise database engines got into nearly every data-storing app over the
last 10 years. Of course, it is fashion, as well. Today you would seem unprofessional storing data
in native file structure. Even if it's better, and if noone really needs the database stuff in the
app.

The database does more than just storing data. It creates and maintains record structures, indexing,
interprets SQL, joins tables, encrypts, password-protects, manages multiple users (IMHO one of the
best reasons to choose a database), filters data...

In the long run, a simple database could cause more work if too simple. The good thing about, say an
Oracle Server, is that you may do almost anything you could think of, once you have got it up and
running. A good example of the opposite is the ASCII driver of the BDE with it's limited
functionality (well, it's not that clever to use this one with all the BDE stuff-overhead), it's
only capable of satisfying very simple demands.

<< But ifyou use the BDE you need thousends of dlls. Why? Could this not be
easier done? Look at Delphi. To access a database you need a TTable, a
TDataSet and special database controls. And all this just to use "a few"
datasets. But then the people are wondering when the exe file is as
large as a 10 gb hd ;) and when the app doesnt work just because a dll
is missing ;).

Yes, the dll stuff is no piece of cake. Borland should concider a model where only 1 dll was
necessary to run a Database, even if this means you'll loose the ability to access different
database engines from the application. They did not succeed in creating an open solution, after all,
since database-specific stuff is to be hard-coded into the app. I would guess that less than 5%,
maybe more like 1%, of datbase-apps written in Delphi are written to handle more than one datbase
engine.

<<I certainly know that Oracle, Paradox & co. have been
established as standard. But I think a new small&simple database
solution would help developers worldwide enormously.

I agree in one aspect of your argumantation: The data-storage and manpulation via controls should be
possible without the overhead of the BDE. What about object-storage functionality support ? All
applications do data mainpulation, and most application store data. In the VCL, you have nothing in
between BDE and the TStrings.LoadFromFile. It would be possible, of course, to use the TPersistent
streaming to create a data storage. We need some generic object persistence mechanism, like the
TPersistent, but most of all: data-aware controls to be used with it ! Then storage could be
designed simple or complex as wished.

--

Bjoerge



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
On Tue, 13 Jul 1999 02:27:43 +0200, "Bj?rge S?ther"

Quote:

>>I really believe that the best reason for creating a BDE replacement including a database engine
>>would be to achieve a behaviour different from the BDE. If you want a square, traditional

Bj?rge you are correct in a lot of what you say but the bit that
annoys me with the BDE is that I have a 230K program that needs 3.6M
of BDE stuff included in the Installation package.

That takes it from a two minute download to a 20 minute from our web
site.

Often there are a lot of applications that just don't need SQL or even
a table structure with cross-linking etc etc.

I for one would jump at a BDE replacement for some apps. Specially if
it only added about 100K to my finished project. I have a customer
using just such an app with the BDE. I could easily have used a
flat-file database as the DB-needs of the project are very basic
indeed.

I could use FlashFiler which is supposed to be a drop in for the BDE
but TurboPower's tech support absolutely stinks. So it will be a long
time before I consider buying **anything** from them again.

There is one other I know of from Elevate software that I believe is a
drop in, well almost and I may just mail them the money.

The bottom line is I think there is a need for a compact flat-file
database for a lot of applications. If it integrates with the
data-aware components even better, but they carry substantial overhead
too.

Stick with it Anthony!

Regards,

Peter Nolan
CEO Nolan Innovation Inc.
*********************************
http://aluminator.tierranet.com
Ph:   (520) 772-9730
Cellular: (520) 713-7016
Fax:  (520) 772-9839
*********************************



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?

Quote:
> I really believe that the best reason for creating a BDE replacement including a database engine
> would be to achieve a behaviour different from the BDE. If you want a square, traditional
> cursor-based relational database, it's just not worth the time creating another one. Personally, I
> would never use a shareware db-engine unless I needed something different from the regular ones.
> I've been checking out a few of them, and I haven't found a good one yet. OK, the BDE isn't
> brilliant, but it is not a disaster compared to the rest of the world of traditional databases.

The reason I'm looking to do one for myself is the following :

1) knowledge/experience.
2) the BDE installation is a nightmare.
3) I need it to compile into my existing exe.
4) It has to be small.

Quote:
> <<The info I need would pertain to creating a small to medium databases,
> not the Interbase, Oracle or Sybase type of monstrous databases.>>

> On my 233MHz Laptop I run Oracle server on NT Workstation 4.0 starting the NT Server and Oracle.
> Startup takes about 2 minutes. On my 3.2 Gb HDD I have 2 small company databases, MS Office, an
> additional Win95, 4 Delphi versions and a lot of projects. I don't quite understand what is
> monstrous about that size ? MS Word uses more RAM than Oracle, and Delphi takes longer to load. The
> only monstrous about those is the price...

And the reason the price is monstrous is because so much functionality that the *typcial* programmer
that needs to use a DB every so often doesn't use. That's why I don't want to make a "monstrous" engine,
just something simple that will do the job.

Quote:
> I believe you would have quite a job outperforming Paradox or Oracle.

I don't think so. I've compared the BDE to the following BDE replacements : DBISAM, Topaz and Halcyon. I
created identical 100,000 record tables and populated them with the same data. I performed the same
benchmarks (filtering, reading, writing, going from BOF to EOF, etc...) on each one of them in the same
manner and the results were surprising. DBISAM and Topaz were disappointing, the BDE was fast but
Halcyon was the fastest of the bunch, and pretty good margin faster than the BDE!!! It also compiles
into an executable and has a footprint of about 250k. I switched to the Halcyon engine at my job and 1)
It's FAST!, 2) it's small, 3) it compiles into an exe and 4) NO BDE INSTALLATION HASSLES!!!

Quote:
> IMHO, the most important feature missing in network-enabled databases from Paradox to oracle is that
> they don't provide a messaging service to notify other users when data changes in the database. If
> you implement this functionality, even I would concider taking a look at such a concept..

That's interesting, would you give me an example or two of what you mean?

Quote:
> The book "Using Delphi 3" by Miller, Powell, et al. described how to create a custom dataset with
> Delphi.

Thanks!

Quote:
> I'm afraid this was almost 100% discouraging. OK, it might be fun creating a datbase engine. It's a
> hell of a lot of work, and you'll learn a lot. But I don't see how these efforts could ever pay off
> unless you really need something different from the traditional Relational DB's.

> Good luck, anyway !
> --

> Bjoerge

Thanks Bjoerge, any input at all is welcome, and I appreciate your help. Apparently criticism is not
held in very high regard but I believe it to be an essential ingredient in discussions, so I welcome it.

Any other thoughts would be appreciated!

Anthony

p.s. Give Halcyon a try, it's FAST and its filtering mechanism is nice! A company called griffin makes
it I think...



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
<<Peter Nolan:

Bj?rge you are correct in a lot of what you say but the bit that
annoys me with the BDE is that I have a 230K program that needs 3.6M
of BDE stuff included in the Installation package.

It's so if you distribute all of the standard BDE. For a Paradox DB, you'll need only about 1.2Mb of
driver DLL's. Maybe it's against Borland guidelines, but I wouldn't care too much. It's silly to
force someone to distribute dBase drivers with a Paradox database.

<<
Often there are a lot of applications that just don't need SQL or even
a table structure with cross-linking etc etc.

I for one would jump at a BDE replacement for some apps. Specially if
it only added about 100K to my finished project. I have a customer
using just such an app with the BDE. I could easily have used a
flat-file database as the DB-needs of the project are very basic
indeed.

IMHO, you're not talking about a BDE replacement. You should concider using a text-file based
TDataSet descendant with no need for special setup or dlls. I mentioned a book with sample code on
such a dataset. But of course, if someone has made a component or suite - go for it !

<<The bottom line is I think there is a need for a compact flat-file
database for a lot of applications. If it integrates with the
data-aware components even better, but they carry substantial overhead
too.>>

Yeah, maybe...I wouldn't wait for Borland to do so...The sizes of everything over there keep
growing...

--

Bjoerge



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?


Quote:

> I for one would jump at a BDE replacement for some apps. Specially if
> it only added about 100K to my finished project. I have a customer
> using just such an app with the BDE. I could easily have used a
> flat-file database as the DB-needs of the project are very basic
> indeed.

The BDE is flawed because it has to be all things to all people. Look at
DBISAM if you want a simple, no frills, fast small desktop database. If you
use client server, there are native interfaces for most of the major
database products. Or use ODBC. As somebody noted in this thread, there are
very few programs that require using multiple databases. Hard enough to get
just one working right, anyway.

Robert



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
<<Anthony:
The reason I'm looking to do one for myself is the following :

1) knowledge/experience.
2) the BDE installation is a nightmare.
3) I need it to compile into my existing exe.
4) It has to be small.
1) A *very* good reason, even if you chose not to use your own, you'd learn a lot about working with
databases...
2) It's not that bad if you do it yourself (find out what .dll's are used, what registry entries are
needed, etc). And - it is possible to do the installation from the .EXE itself.
But- of course, I understand you disliking BDE installation - I've been into it for 3 years now.
Then it's easy...;^D

<<

Quote:
> I believe you would have quite a job outperforming Paradox or Oracle.

I don't think so. I've compared the BDE to the following BDE replacements : DBISAM, Topaz and
Halcyon. I
created identical 100,000 record tables and populated them with the same data. I performed the same
benchmarks (filtering, reading, writing, going from BOF to EOF, etc...) on each one of them in the
same
manner and the results were surprising. DBISAM and Topaz were disappointing, the BDE was fast but
Halcyon was the fastest of the bunch, and pretty good margin faster than the BDE!!! It also compiles
into an executable and has a footprint of about 250k. I switched to the Halcyon engine at my job and
1)
It's FAST!, 2) it's small, 3) it compiles into an exe and 4) NO BDE INSTALLATION HASSLES!!!
I have downloaded the Halcyon database engine and I'm now about to test it. Thanks for the tip !

<<

Quote:
> IMHO, the most important feature missing in network-enabled databases from Paradox to oracle is
that
> they don't provide a messaging service to notify other users when data changes in the database. If
> you implement this functionality, even I would concider taking a look at such a concept..

That's interesting, would you give me an example or two of what you mean?

In a multi-user environment you'd like to receive a notification from the database server whenever
data was changed in the database. Today you'll have to refresh the data manually from every client,
not knowing if anything has happened at all. The way I've been dealing with this is to create a
separate table storing the current update serialno for each dataset, so that a client can open this
table, compare to the existing serialno's and refresh the data if a higher no is encountered. A much
better solution would be if the server itself broadcasted a message to all loggedon clients that
changes so and so has occurred. then the clients could decide for themselves whether to reload or
not. Actually, a beautiful Client/Server concept could be created where the server and the clients
were actually *talking* together. Where bandwidth is a problem (quite usual), The server could
broadcast data rather than having all clients asking for the same data.. A small service app with
say 100 clients could be run with small bandwidth requirements using sophisticated caching/version
control/packing(zipping).
OK, this was a bit far, maybe, but the notification is important ! It should be possible to use this
concept (optionally, of course) for file-based db's as well. Of course, the file couldn't send a
message, but it could store data versions easy accessible for all other clients upone each change.

--

Bjoerge



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
Robert,

<< Look at DBISAM if you want a simple, no frills, fast small desktop
database. >>

Geez Robert, I thought we had at least a couple of frills. ;-)

Tim Young
Elevate Software
www.elevatesoft.com



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
On Wed, 14 Jul 1999 00:17:44 +0200, "Bj?rge S?ther"

[...]

Quote:
>It's so if you distribute all of the standard BDE. For a Paradox
>DB, you'll need only about 1.2Mb of driver DLL's. Maybe it's
>against Borland guidelines, but I wouldn't care too much. It's
>silly to force someone to distribute dBase drivers with a Paradox
>database.

[...]

This is does not contradict BDE redistribution requirements stipulated by
Borland. It is discussed in section 3.3 "Partial BDE Installs" of the text
file BDEDEPLOY.TXT, found in the main BDE directory.

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Steve Koterski         "Television is a medium because anything well done
Felton, CA             is rare."
                                                 -- Fred Allen (1894-1956)



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?

Quote:
> I have downloaded the Halcyon database engine and I'm now about to test it. Thanks for the tip !

No problemo!

Quote:
> In a multi-user environment you'd like to receive a notification from the database server whenever
> data was changed in the database. Today you'll have to refresh the data manually from every client,
> not knowing if anything has happened at all. The way I've been dealing with this is to create a
> separate table storing the current update serialno for each dataset, so that a client can open this
> table, compare to the existing serialno's and refresh the data if a higher no is encountered. A much
> better solution would be if the server itself broadcasted a message to all loggedon clients that
> changes so and so has occurred. then the clients could decide for themselves whether to reload or
> not. Actually, a beautiful Client/Server concept could be created where the server and the clients
> were actually *talking* together. Where bandwidth is a problem (quite usual), The server could
> broadcast data rather than having all clients asking for the same data.. A small service app with
> say 100 clients could be run with small bandwidth requirements using sophisticated caching/version
> control/packing(zipping).
> OK, this was a bit far, maybe, but the notification is important ! It should be possible to use this
> concept (optionally, of course) for file-based db's as well. Of course, the file couldn't send a
> message, but it could store data versions easy accessible for all other clients upone each change.

That would be very useful. I don't see why this would be a big deal to implement, why haven't they done
so?

cul8r allig8r!

Anthony



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
<<Steve Koterski:

Quote:
>Bjoerge Saether:
>It's so if you distribute all of the standard BDE. For a Paradox
>DB, you'll need only about 1.2Mb of driver DLL's. Maybe it's
>against Borland guidelines, but I wouldn't care too much. It's
>silly to force someone to distribute dBase drivers with a Paradox
>database.

This is does not contradict BDE redistribution requirements stipulated by
Borland. It is discussed in section 3.3 "Partial BDE Installs" of the text
file BDEDEPLOY.TXT, found in the main BDE directory.

That's good, and I withdraw my somewhat agressive statement. The statement (that you have to
distribute it all) has been repeated so many times that I took it for for the truth. So - I'm no
criminal ! Good ! ;^D)

--

Bjoerge



Wed, 18 Jun 1902 08:00:00 GMT  
 Programming a database, any info?
On Thu, 15 Jul 1999 00:54:04 +0200, "Bj?rge S?ther"

[...]

Quote:
>That's good, and I withdraw my somewhat agressive statement. The
>statement (that you have to distribute it all) has been repeated
>so many times that I took it for for the truth. So - I'm no
>criminal ! Good ! ;^D)

Criminal?! Just the opposite. You're spreading correct information. Where I
come from, that's considered a Good Thing(TM).

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Steve Koterski         "Television is a medium because anything well done
Felton, CA             is rare."
                                                 -- Fred Allen (1894-1956)



Wed, 18 Jun 1902 08:00:00 GMT  
 
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