which RDBMS to use...

Hello,

I would like to migrate to a SQL database, but I wonder which RDBMS to
use.
My first priority is performance, but I would also like to update and
insert data from .NET programs. So I would rather prefer to use SQL
Server which is the favorite database for .NET programs...

I've read in the SQLRDD Manual that: it's better to "avoid using
Synthetic Indexes with other databases than Postgres and Oracle."
Does that mean that indexes aren't possible with SQL Server ?
In my current clipper application, I use many .NTX indexes, skip,
goto, seek instructions. Will the use of indexes greatly improve the
performances when running on a SQL database ?

On the other hand, it is said that one of the disadvantage of using
indexes is "prohibition to UPDATE or INSERT in table from outside xHb
application".
It is a non negligible problem as I would like to update and insert
data from .NET programs. So I would like to be sure that indexes are
necessary to have acceptable performances.

In short, it seems that I must choose:
-either to be efficient with xHarbour: in that case I must use
Postgres or Oracle to use indexes.
-either to have my data available to other platform. As my favorite
one is .NET, I would choose SQL Server in that case.

Am I right or should I take other parameters into account ?
Any advices will be welcome. :-)

Thank you in advance.

mathmax

Don't forget to check into Advantage Database Server. It has .net/sql
connection but can still use dbf files.

maximeandrighetto@gmail.com wrote:
> Hello,
>
> I would like to migrate to a SQL database, but I wonder which RDBMS to
> use.
> My first priority is performance, but I would also like to update and
> insert data from .NET programs. So I would rather prefer to use SQL
> Server which is the favorite database for .NET programs...
>
> I've read in the SQLRDD Manual that: it's better to "avoid using
> Synthetic Indexes with other databases than Postgres and Oracle."
> Does that mean that indexes aren't possible with SQL Server ?
> In my current clipper application, I use many .NTX indexes, skip,
> goto, seek instructions. Will the use of indexes greatly improve the
> performances when running on a SQL database ?
>
> On the other hand, it is said that one of the disadvantage of using
> indexes is "prohibition to UPDATE or INSERT in table from outside xHb
> application".
> It is a non negligible problem as I would like to update and insert
> data from .NET programs. So I would like to be sure that indexes are
> necessary to have acceptable performances.
>
> In short, it seems that I must choose:
> -either to be efficient with xHarbour: in that case I must use
> Postgres or Oracle to use indexes.
> -either to have my data available to other platform. As my favorite
> one is .NET, I would choose SQL Server in that case.
>
> Am I right or should I take other parameters into account ?
> Any advices will be welcome. :-)
>
> Thank you in advance.
>
> mathmax
>

Mathmax,

> I've read in the SQLRDD Manual that: it's better to "avoid using
> Synthetic Indexes with other databases than Postgres and Oracle."
> Does that mean that indexes aren't possible with SQL Server ?

No, it means you simply do not need such approach with other
databases. Only with Oracle and Postgres.

> In my current clipper application, I use many .NTX indexes, skip,
> goto, seek instructions. Will the use of indexes greatly improve the
> performances when running on a SQL database ?

Yes, for sure you will need indexes.

> On the other hand, it is said that one of the disadvantage of using
> indexes is "prohibition to UPDATE or INSERT in table from outside xHb
> application".
> It is a non negligible problem as I would like to update and insert
> data from .NET programs. So I would like to be sure that indexes are
> necessary to have acceptable performances.

Indexes are necessary and you can safely UPDATE, INSERT or DELETE
from .NET applications.

> In short, it seems that I must choose:
> -either to be efficient with xHarbour: in that case I must use
> Postgres or Oracle to use indexes.
> -either to have my data available to other platform. As my favorite
> one is .NET, I would choose SQL Server in that case.

No, this is a complete misunderstanding.

> Am I right or should I take other parameters into account ?
> Any advices will be welcome. :-)

You can safely update your MSSQL tables from other applications. Just
don't forget to NOT write blanks in strings right side.

Marcelo

Mathmax,

> I would like to migrate to a SQL database, but I wonder which RDBMS to
> use.

If you use SQLRDD you can avoid such decision right now and simply
migrate your app. With time, you will find out whats the best database
for you.

> My first priority is performance, but I would also like to update and
> insert data from .NET programs. So I would rather prefer to use SQL
> Server which is the favorite database for .NET programs...
>
> I've read in the SQLRDD Manual that: it's better to "avoid using
> Synthetic Indexes with other databases than Postgres and Oracle."
> Does that mean that indexes aren't possible with SQL Server ?

You can use indexes in MSSQL for sure. You may want to download demo
and try the samples for yourself.

> In my current clipper application, I use many .NTX indexes, skip,
> goto, seek instructions. Will the use of indexes greatly improve the
> performances when running on a SQL database ?

Using indexes will increase the performance as well as it does in DBF.

> On the other hand, it is said that one of the disadvantage of using
> indexes is "prohibition to UPDATE or INSERT in table from outside xHb
> application".

This is true only if you use irregular index expressions like
"MyFun()" or "SubStr(fied,3,2)". Otherwise you can for sure make
changes from other apps. Just don't forget to NOT write blanks in
right side of strings.

> It is a non negligible problem as I would like to update and insert
> data from .NET programs. So I would like to be sure that indexes are
> necessary to have acceptable performances.

Yes, they are.

> In short, it seems that I must choose:
> -either to be efficient with xHarbour: in that case I must use
> Postgres or Oracle to use indexes.

Thats a complete misunderstanding, as above.

> -either to have my data available to other platform. As my favorite
> one is .NET, I would choose SQL Server in that case.
>
> Am I right or should I take other parameters into account ?
> Any advices will be welcome. :-)

All I can say is MSSQL is *my* preferred database and you can safely
share your tables with .NET applications.

Marcelo

Mathmax,

> I've read in the SQLRDD Manual that: it's better to "avoid using
> Synthetic Indexes with other databases than Postgres and Oracle."
> Does that mean that indexes aren't possible with SQL Server ?

No, it means you simply do not need such approach with other
databases. Only with Oracle and Postgres.

> In my current clipper application, I use many .NTX indexes, skip,
> goto, seek instructions. Will the use of indexes greatly improve the
> performances when running on a SQL database ?

Yes, for sure you will need indexes.

> On the other hand, it is said that one of the disadvantage of using
> indexes is "prohibition to UPDATE or INSERT in table from outside xHb
> application".
> It is a non negligible problem as I would like to update and insert
> data from .NET programs. So I would like to be sure that indexes are
> necessary to have acceptable performances.

Indexes are necessary and you can safely UPDATE, INSERT or DELETE
from .NET applications.

> In short, it seems that I must choose:
> -either to be efficient with xHarbour: in that case I must use
> Postgres or Oracle to use indexes.
> -either to have my data available to other platform. As my favorite
> one is .NET, I would choose SQL Server in that case.

No, this is a complete misunderstanding.

> Am I right or should I take other parameters into account ?
> Any advices will be welcome. :-)

You can safely update your MSSQL tables from other applications. Just
don't forget to NOT write blanks in strings right side.

Marcelo

maximeandrighetto@gmail.com escribió:
>
> Am I right or should I take other parameters into account ?
> Any advices will be welcome. :-)

Yes, MONEY !!!!!

In my experience, you get what you pay talking about RDBMS, don't expect
the same features in a commercial "expensive" product, agains a free
or open sourcer product.

"Something" must Oracle, SQL Server, Informix have to have that they are
pricy, and "something" have to have or not have MySQL, Firebird or
Postgre that they are free.

Regards

Rene Flores
http://www.ciber-tec.com
>
> Thank you in advance.
>
> mathmax
>

I would rather prefer to avoid using Advantage Database Server because
of the price.

>No, it means you simply do not need such approach with other
>databases. Only with Oracle and Postgres.

Which approach should I have with SQL Server for example?

>No, this is a complete misunderstanding.

So I don't understand what does this sentence mean:
"prohibition to UPDATE or INSERT in table from outside xHb
application"
Could you clarify it ?

>You can safely update your MSSQL tables from other applications. >Just don't forget to NOT write blanks in strings right side.

You mean I should calculate the index for each row updated or inserted
completing it with white spaces ? Is it possible to define a trigger
on the database so that this index will be calculated automatically ?

Thanks,

mathmax

Mathmax,

> >No, it means you simply do not need such approach with other
> >databases. Only with Oracle and Postgres.
>
> Which approach should I have with SQL Server for example?

Nothing special. Just use SQLRDD as you can find in samples.

> >No, this is a complete misunderstanding.
>
> So I don't understand what does this sentence mean:
> "prohibition to UPDATE or INSERT in table from outside xHb
> application"
> Could you clarify it ?

If you take just one sentence and read it out of context you can be
driven to misunderstanding. Please read again the whole chapter and I
think you will find the real meaning for yourself.

> >You can safely update your MSSQL tables from other applications. >Just don't forget to NOT write blanks in strings right side.
>
> You mean I should calculate the index for each row updated or inserted
> completing it with white spaces ? Is it possible to define a trigger
> on the database so that this index will be calculated automatically ?

No no no. I mean SQLRDD does not write spaces in right side of
character fields. So you may want to do the same from within your .NET
application. This was just a hint for you.

Marcelo

Sorry, in the previous messages, each time I spoke about indexes, I
wanted to say Synthetics indexes.
So it seems that those type of indexes are just usable in Postgres or
Oracle and not with SQL Server, am I right ?

First I would like to know if we must choose either to use synthetic
indexes or physical indexes or if it's possible/better to use both of
them. In case we must choose, which is the most efficient ?
Do Synthetics indexes greatly improve performances in case of using
many instruction such as skip, goto or seek ? Or normal indexes will
be sufficient ?

If I have well understood, synthetics indexes make it impossible to
insert/update data other programs than xHarbour, doesn't it ?

Regards,

mathmax

Mathmax,

> Sorry, in the previous messages, each time I spoke about indexes, I
> wanted to say Synthetics indexes.
> So it seems that those type of indexes are just usable in Postgres or
> Oracle and not with SQL Server, am I right ?

Wrong. Docs does not say that.

> First I would like to know if we must choose either to use synthetic
> indexes or physical indexes or if it's possible/better to use both of
> them. In case we must choose, which is the most efficient ?

Let SQLRDD decide for you. Its is automatic.

> Do Synthetics indexes greatly improve performances in case of using
> many instruction such as skip, goto or seek ? Or normal indexes will
> be sufficient ?

In MSSQL it is needed only if you do not use a regular index
expression, as stated in previos message.

> If I have well understood, synthetics indexes make it impossible to
> insert/update data other programs than xHarbour, doesn't it ?

No but you have to fill the INKEY_??? column from within your .NET
application.

Marcelo