indexes 1

[Fursten]

Hi,

I´m reading one part of Crystal User´s Guide and it says that indexes are important to performance when using data files, but not when using SQL databases (like SQL Server)... Why?

I understand that indexes are necessary, but why aren´t they important in the case of SQL databases?

Thank you,

Sérgio Oliveira

 

[synapsevampire]

Hmmm, sounds like something is taken out of context here.

Indexes are always important!

You may have some control over which index is in use with non-SQL databases, whereas the database should decide that for you when using a SQL database (though it can be overidden using hints, etc., but that's beyond the scope of this thread for now I think).

-k

http://www.informeddatadecisions.com

kai@informeddatadecisions.com

 

[Fursten]

Hi,

I think like you... but they say this, and I don´t understand why: when talking about report performance it is saied:

"Since indexes are not critical with SQL Data, the primary concern with both linked tables and subreports is wether or not there is a selection formula in the primary report that puts range limits on Table A" Crystal user guide pag 499

What it seems to me is that it is saying that for crystal, indexes in sql tables doesn´t matter... and I don´t undestand why. Why aren´t they critical? Is that because we are using selection formulas? hmm... maybe is because that.

But in non SQL data couldn´t we use selection formula too? (never used non SQL data...).

thank you for your opinion on this.

Sérgio Oliveira

 

[synapsevampire]

I think that they are just alerting you that you have some control over indexes for non-SQL databases, so they are of concern (more critical) to you.

It was poorly phrased by Crystal, it should have said that you have more control over indexes for non-SQL databases.

-k

http://www.informeddatadecisions.com

kai@informeddatadecisions.com

 

[Fursten]

yes, it must be it. Maybe they don´t even think of using where clauses without those columns to be index in SQL Server.

Thank you again!

Sérgio Oliveira