In sybase for the column what datatype the sybase expert's suggest
either char or varchar?

I heared that while doing update statistics ... the varchar is costlier 
than the space occupied by char.

Please share your knowledge.

Thanks and Best Regards
Gopi Chand T.

The choice between "varchar" and "char" doesn't have much of anything to
do with the performance of "update statistics" that I know of.  There is
a small performance penalty for accessing variable length data on the
row, but it would only be notable under very high load.

Take a look at the manuals discussing datatypes to make your own
judgments.  The basic rule-of-thumb is that if you have a column whose
length varies widely, but on average is small, use varchar.  Note also,
that "char(x) NULL" is internally stored as "varchar(x)".

http://manuals.sybase.com:80/onlinebooks/group-as/asg1250e/refman/@Generic__BookTextView/3571;pt=3571#X

Gopi_Chand_T wrote:
> 
> In sybase for the column what datatype the sybase expert's suggest
> either char or varchar?
> 
> I heared that while doing update statistics ... the varchar is costlier
> than the space occupied by char.
> 
> Please share your knowledge.
> 
> Thanks and Best Regards
> Gopi Chand T.

I am not an expert, just an application developper.
I lost my hair with Oracle and char datatype because of this ( i use T-SQL
Syntax, but imagine that it runs on Oracle) :
Declare @foo char(2)
begin
 select @foo = 'A'
 if @foo = 'A'
   -- never reach this point !!!!
 else
   -- always execute this !!
end
Because @foo contains 'A ' (or ' A') wich is always different from 'A'.

I do not know what is ASE behaviour, because i am writing from home.
But i always use
Char(1)
Varchar(n) where n>=2

"Sherlock, Kevin" <ksherlo@qwest.com.nospam> a �crit dans le message news:
3EEDD6E0.7D1DE0AB@qwest.com.nospam...
> The choice between "varchar" and "char" doesn't have much of anything to
> do with the performance of "update statistics" that I know of.  There is
> a small performance penalty for accessing variable length data on the
> row, but it would only be notable under very high load.
>
> Take a look at the manuals discussing datatypes to make your own
> judgments.  The basic rule-of-thumb is that if you have a column whose
> length varies widely, but on average is small, use varchar.  Note also,
> that "char(x) NULL" is internally stored as "varchar(x)".
>
>
http://manuals.sybase.com:80/onlinebooks/group-as/asg1250e/refman/@Generic__
BookTextView/3571;pt=3571#X
>
> Gopi_Chand_T wrote:
> >
> > In sybase for the column what datatype the sybase expert's suggest
> > either char or varchar?
> >
> > I heared that while doing update statistics ... the varchar is costlier
> > than the space occupied by char.
> >
> > Please share your knowledge.
> >
> > Thanks and Best Regards
> > Gopi Chand T.

> Declare @foo char(2)
> begin
>  select @foo = 'A'
>  if @foo = 'A'
>    -- never reach this point !!!!

This is where you will always end up in ASE.  In the case of both the
assignment, and the conditional expressions, the literal 'A' is
implicitly converted to a "char(2)".

>  else
>    -- always execute this !!

"Olivier Citeau" wrote:
> 
> I am not an expert, just an application developper.
> I lost my hair with Oracle and char datatype because of this ( i use T-SQL
> Syntax, but imagine that it runs on Oracle) :
> Declare @foo char(2)
> begin
>  select @foo = 'A'
>  if @foo = 'A'
>    -- never reach this point !!!!
>  else
>    -- always execute this !!
> end
> Because @foo contains 'A ' (or ' A') wich is always different from 'A'.
> 
> I do not know what is ASE behaviour, because i am writing from home.
> But i always use
> Char(1)
> Varchar(n) where n>=2
> 
> "Sherlock, Kevin" <ksherlo@qwest.com.nospam> a �crit dans le message news:
> 3EEDD6E0.7D1DE0AB@qwest.com.nospam...
> > The choice between "varchar" and "char" doesn't have much of anything to
> > do with the performance of "update statistics" that I know of.  There is
> > a small performance penalty for accessing variable length data on the
> > row, but it would only be notable under very high load.
> >
> > Take a look at the manuals discussing datatypes to make your own
> > judgments.  The basic rule-of-thumb is that if you have a column whose
> > length varies widely, but on average is small, use varchar.  Note also,
> > that "char(x) NULL" is internally stored as "varchar(x)".
> >
> >
> http://manuals.sybase.com:80/onlinebooks/group-as/asg1250e/refman/@Generic__
> BookTextView/3571;pt=3571#X
> >
> > Gopi_Chand_T wrote:
> > >
> > > In sybase for the column what datatype the sybase expert's suggest
> > > either char or varchar?
> > >
> > > I heared that while doing update statistics ... the varchar is costlier
> > > than the space occupied by char.
> > >
> > > Please share your knowledge.
> > >
> > > Thanks and Best Regards
> > > Gopi Chand T.