Performance: use linked tables or command object? Crystal XI

[thementornetwork]

I am using Crystal XI.

Someone told me that replacing linked tables by a command object will enhance performance and make reports run faster.

Is it always true?

Currently there is still too little data to test on and be able to tell the difference, but after the data conversion, we may be talking about tens of thousands records and performance will become a main issue. That's why I'd like to have my reports built "right" from the start as much as possible.

At the moment, I have been using linked tables only.

Thanks for your input.

 

[BOBJProduct]

It's not always true that it's faster, but if you've got the SQL skills, I'd recommend a command object. You have complete control over what gets pushed down to the database.

Linked tables are ok, but sometimes you want to do some calculations on the database side, and sometimes you want to hand-tune SQL. Command objects allow for this.

The only downside of command objects in XI is they don't support multi-value parameters. That downside is addressed in CR 2008. Command objects in CR 2008 support multi-value parameters.

Cheers, Blair

 

[beltmanjr]

Lets add that I have been made aware that you should not use a combination of commands and linked tables as it kind a pulls down all data to crystal before it starts any kind of filtering and thus slows things down.

 

[CrystalLion]

I have not experience in creating command objects in place of linking. Can anyone recommend a good resource for learning how to do this.

 

[AndrewBaines]

Easy way is to write your report the regular way, then cut, paste and modify the SQL it generates in a command object.

Andrew Baines

http://www.pursuittechnology.co.uk

 

[beltmanjr]

The command statement is simply like creating a SQL query. Andrew's advice is very good for if you dont understand SQL

 

[CrystalLion]

In order to add a command, the help text indicates I need to have the Repository activated. Every time I try to activate the Repository, I hit a dead end. I am running CR XI on a stand-alone pc and apparently I don't have a Central Management Server to log on to. The authentication dropdown lists ENTERPRISE, LDAP, WIndows AD, and Windows NT. None of these work with my password. When I installed Crystal, I selected everything I could select to be installed. Does the repository only come with the Enterprise edition?

L

 

[AndrewBaines]

Are you selecting the right thing? When you select the data source, there should be a Add Command option. You don't need Enterprise to use Commands (though it does extend functionality).
I think you may be trying to add a function from the repository.

Andrew Baines

http://www.pursuittechnology.co.uk

 

[CrystalLion]

I am selecting:
Database
Database Expert
in the data window, there is no Add Command.

Am I in the wrong place?

 

[CrystalLion]

Let me clarify.

When I expand each of the available items
Current Connections
Favorites
History
Create New Connection
Repository

Add Command does not appear anywhere.

 

[lbass]

You have to select your datasource (within one of those categories), and then when the tables appear, the "add command" will appear at the top of the table list.

-LB

 

[CrystalLion]

Dah!

Thanks LB.

 

[hilfy]

Also, Add Command is not available for all databases or types of connections - such as ODBC vs. native access.

-Dell

A computer only does what you actually told it to do - not what you thought you told it to do.

 

[RustyAfro]

My two cents-

Use commands only when you can't accomplish your goal with Linked Tables. Not everyone is SQL savvy and if you build the report using native Crystal functions (Linked Table, SQL Expressions, etc), it will be easier for the next person who takes over the maintenance of your report.