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Re: st: Saving datasets temporarily - switching back and forth between two datasets


From   Phil Clayton <philclayton@internode.on.net>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Saving datasets temporarily - switching back and forth between two datasets
Date   Sat, 19 Nov 2011 09:11:25 +1100

Have you looked at -tempfile-? It allows you to save datasets to a temporary file from within a do-file. You don't need to specify the file name and they automatically get deleted.

So you could, for example, do something like this:
use masterdataset
(refine)
tempfile master
save `master'
use usingdataset1
(refine)
tempfile using1
save `using1'
use usingdataset2
(refine)
tempfile using2
save `using2'
use `master'
merge ...

You may also want to check out -mmerge- which is an extension to -merge- (available from SSC). It allows you to do things such as:
- merge on a variable that has a different name in each dataset
- rename variables from the "using" dataset on the fly
- specify that you only want to merge in a subset of observations from the "using" dataset

I often find that with -mmerge- I can accomplish what I need in one command, or occasionally two if I need to remove some duplicates after merging.

Phil

On 19/11/2011, at 8:54 AM, Ben Hoen wrote:

> I am executing a merge between one main dataset and a few others.  Some of
> the other datasets need some additional refining before they can be merged
> easily (e.g., changing variable names, culling out duplicates), but I have
> no need to save off these temporary versions.
> 
> Is it possible to hold the main dataset in "memory" while I quickly refine a
> using dataset, then save IT into memory, from where I perform the merge?
> 
> Tangentially, if I was to save off a temporary file to merge to, can I erase
> that file from a do-file?  
> 
> Did that make sense?
> 
> Ben
> 
> Ben Hoen
> Principal Research Associate
> Lawrence Berkeley National Laboratory
> Office: 845-758-1896
> Cell: 718-812-7589
> bhoen@lbl.gov
> http://eetd.lbl.gov/ea/emp/staff/hoen.html
> 
> 
> 
> 
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