Maximum columns in a table

[dilipkumar]

What is column count in Lianja table ?

is it 256 columns? or extended ?

Thanks,
Dilip

[HankFay]

It is 256, per System Capacities in the Lianja Wiki: http://www.lianja.com/doc/index.php/System_Capacities

BTW: a Google search on "lianja max number of columns" brings up that page. I've found that using Google to search for Lianja questions often brings me to the right Wiki page.

Hank

[dilipkumar]

If that is the case, then providing large table size will not be much useful. Because of the 256 column ristriction. Vfp not able to take the full advantage of using third party RDBMS.

The vfp cursor also having that ristriction.
Because of this reason. Most of the vfp ERP apps are moving to .net.

If lianja is also same then This will be a big show stopper to develop apps with lianja backend. Why can't break this ristriction in lianja.


I gave demo about lianja in my company. They asked me this question. They said, if lianja removes that restriction. They can buy the licence and try.

Barry,
Is it possible to do?

Thanks,
Dilip

[HankFay]

Hi Dilip,

VFP cursors' big limitation (other than crapping out randomly on SMB2 and SMB3) was the 2GB file limit, not the 256 column limit.

I find it hard to imagine a 4th Normal Form database having a 256 column table. (For a quick review of normalization: http://www.bkent.net/Doc/simple5.htm)

Hank

[dilipkumar]

Hi Hank,

So, it is not possible in Lianja to extent the column limit right?

Thanks,
Dilip

[HankFay]

Hi Dilip,

that is correct. Nor should it be. Performance goes down with additional columns unless you take extreme steps to prevent that from happening.

The literature on # of columns is clear: if you have a large number of columns in you table(s), you almost certainly have an under-designed database. I'm sure there are exceptions. But to be classified an exception, I would require an analysis of what Normal Form the database exhibits.

I've had a few occasions over the past 20 years to examine requests for more columns and in each case the solution was to make domain and table match up. If you have a real world example of a table that you think would require more than 256 columns, and think that the table is consistent with Fourth Normal Form, go ahead and post it here, 1 field per line, with field name and short description. It could be a good learning experience for us all.

Hank

[dilipkumar]

Hi Hank,

I agree with you. IF it is a new application that can design as you said. But the problem is with migration.
The applications which are using more than 256 columns, those will have problem.

Not only with VFP migration, But also with .NET apps who what to migrate to Lianja after including C# and VB.net scripting languages in lianja 5.0

extending more than 256 columns is required. Ms SqlServer is supporting 1024 columns per table. Oracle table is supporting 1000 columns. It depends on the application to use more than 256 columns or not. we should give free hand to use. If anybody is more concern about the performance, they will not use more columns.

Thanks,
Dilip

[hmischel@diligentsystems.com]

Hi Dilip,

My new apps are running in parallel with my older apps. The data is mostly on SQL Server as I have many hundreds of stored procedures.
I still use those stored procedures on SQL Server and return the data to Lianja. The same way I would in C# or C++.

I call the stored procedure using SQLConnect and return the data into a temporary table.

If you have an app that that needs a 500 columns, just keep the data in SQL Server. I cant imagine that you need to view that many columns at once.
Just grab what you need.

Or if you really want the data in Lianja, logically partition multiple tables. It's not a difficult work around.

Herb

[phabio]

Hi Dilip,
if you just want to "see" the data, you can always use a report ..

Ciao
Fabio

[dilipkumar]

Hi Herb

I agree with you. But, If more than 256 columns are not required, why SqlServer and Oracle are support 1024 columns ?
as you said, if we want to use more than 256 columns to use, depend on SqlServer/Oracle/etc., . That means Lianja database is backward comparing to other RDBMS?

So, as like VFP we have to consider Lianja also as a front-end tool only?. if we want to compete in market, we should not tell excuses. the same question may raise many others after considering lianja.

I don't want Lianja Database to be backward because of this reason.

Thanks,
Dilip