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Re: Re: st: .dta storage, why is too big?


From   "Clyde Schechter" <clyde.schechter@einstein.yu.edu>
To   statalist@hsphsun2.harvard.edu
Subject   Re: Re: st: .dta storage, why is too big?
Date   Wed, 8 Jun 2011 12:19:34 -0700

Clarification to my earlier post (below)

Stata's specifications for the .dta format includes some "overhead" that
describes the contents of the file.  So, of course, one could create a toy
data set that has 1 observation on 1 byte variable, and it would be larger
as .dta than as .txt.

What I meant to say is that I have never seen a real-world data set where
the .dta is larger than the .txt version.

Clyde Schechter


On Tue, 7 Jun 2011, Daniel Marcelino wrote:

> Hello for all,
>
> today I came across my old and new files size, R and Stata storage
respectively. This got me thinking about why Stata compression is too
inefficient compared to R? Even thought I use variable attributes like
labels R compression is incredible. For example, 530 mb of Stata file
turns into 9 mb R file and about 330 mb as txt file.  So, my point is:
do you know any trick to compress Stata files addition to command line
"compress".

and Daniel Feenberg replied that Stata doesn't do any "Shannonesque
compression."

That is true, but I really wonder if there isn't something wrong with
Daniel Marcelino's Stata installation, or something very odd about the
file that provoked his post.  I have been using Stata since version 4 and
I have _never_ in all those years encountered a data set that was larger
as .dta than as a text file.  The .dta version may not be much smaller
than the text version, but, I have never seen it be larger.


Clyde Schechter
Associate Professor of Family & Social Medicine
Albert Einstein College of Medicine, Bronx, NY, USA

Please note new e-mail address: clyde.schechter@einstein.yu.edu



Clyde Schechter, MA MD
Associate Professor of Family & Social Medicine

Please note new e-mail address: clyde.schechter@einstein.yu.edu

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