What is the tip for shrink SASdata

Reply
Frequent Contributor
Posts: 99

What is the tip for shrink SASdata

Hi,

I have a sas7dbat file

NameTypeLengthFormatInformatLabelComments
branch_codeCharacter7$CHAR7.$CHAR7.BRANCH CODEAll value are of three english character
PFS Cust Segment CodeCharacter6   All value are of three english character
LoanCMPCharacter1    
OutstandingCMPCharacter1    
NationCMPCharacter3    
VerdateCharacter204   All value are of 6 numberic character as "201112"
New Cust IndCharacter2$2.00 $2.00 New Cust IndAll value are of one english character
OccupationCMPCharacter13   The longest value for this field is 10 english characters.
cmpCharacter25   The longest value for this field is 10 english characters.
NoCountNumeric8   ??it's length limit was 8, but I do find a value over 100M
TRBLevelCharacter9    

with 3.2M records and 837M disk space.

How to shrink it?

Thanks in advance.

Esteemed Advisor
Posts: 7,293

What is the tip for shrink SASdata

This sounds like a quiz question.  Since unnecessarily used space still takes up space, you are wasting a lot of space in all of the character fields.  As for the numeric one, read the documentation: http://support.sas.com/documentation/cdl/en/hostunx/61879/HTML/default/viewer.htm#a000344718.htm

Regular Contributor
Posts: 233

What is the tip for shrink SASdata

Zipping the data set might help.

Respected Advisor
Posts: 4,973

What is the tip for shrink SASdata

First, you have to be very sure that your "Comments" are correct.  For example, you have to be 100% certain that VERDATE is never longer than six characters.  Since BRANCH_CODE uses a $CHAR7. format/informat, it is not enough to print some values.  The $CHAR formats imply that the variable might contain leading blanks.  You have to determine if it does contain leading blanks, whether you would like to left-hand-justify the characters.  The length needed might be impacted, but the sorted order might change as well.

After you have completed your analysis, set the option and the lengths appropriately.  For example:

options compess=YES;

data my_data;

   length VERDATE $ 6;

   set my_data;

run;

Set the length BEFORE the SET statement, for as many variables as you have analyzed to verify the needed length.

Good luck.

Super User
Super User
Posts: 6,326

What is the tip for shrink SASdata

You will probably get pretty good reduction by just using the COMPRESS=YES option.

If you are correct about the maximum lengths of the actual data then you can make the file smaller by re-creating it with shorter character variables.

Where you would want to avoid this is if this is just one example of a number of datasets that you have with this structure.  The other potential datasets might have longer actual values.

There is usually not much value (and some risk) in storing numbers in less than 8 bytes.  SAS always stores numbers are floating point.

The easiest way to recreate with shorter lengths is to set the length before referencing the original data (as suggested above).

Watch out for the variables that have permanent formats attached. You should change those (or better just remove them).  You will need to put the FORMAT statement after the set statement for it to win out.

data want ;

   length branch_code $3 .... ;

   set old ;

   format _character_ ;

run;

Frequent Contributor
Posts: 99

What is the tip for shrink SASdata

Dear All,

Thank you very much for your help and sharing thoughts.

Ask a Question
Discussion stats
  • 5 replies
  • 535 views
  • 0 likes
  • 5 in conversation