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From | Richard Williams <richardwilliams.ndu@gmail.com> |
To | statalist@hsphsun2.harvard.edu, statalist@hsphsun2.harvard.edu |
Subject | Re: st: How many observations can Stata 11 handle? |
Date | Wed, 15 Feb 2012 09:22:06 -0500 |
At 09:02 AM 2/15/2012, Maarten Buis wrote:
On Wed, Feb 15, 2012 at 2:42 PM, Tunga Kantarcı wrote: > Here is a short question. What is the maximum number of observations > that Stata 11 can handle? -help limits- > I have an administrative data set which > includes observations for about 3 million unique individuals, for 20 > variables. I very much doubt that the maximum number of observations is the problem here (unless you are using Small Stata, in which case you get what you pay for). Instead I suspect a problem with memory, specifically I suspect that one or more variables are stored as very long strings. The solution to that is to either not load that/those variable(s) by using -use varlist using filename- instead of -use filename-. You can spot the offending variables using -desc using filename-. Alternatively you can load only the offending variables, fix them and merge them with the rest of the variables. > I plan to draw a sample from the data set using SPSS and transfer the > data to Stata 11 with the Stat-transfer data conversion program. no need to use SPSS: to draw a 70% sample before opening the data you can type -use <filename> if runiform() < .7-
Stat transfer can also draw a random sample for you. This may be better if the size of the data set is a problem for Stata. See the Observations tab in Stat Transfer. Also see the Options tab for setting the seed if you want to be able to reproduce the exact same sample later. Stat Transfer also tells you how the vars are stored, which can be helpful for identifying string vars if that is what is causing the problem.
------------------------------------------- Richard Williams, Notre Dame Dept of Sociology OFFICE: (574)631-6668, (574)631-6463 HOME: (574)289-5227 EMAIL: Richard.A.Williams.5@ND.Edu WWW: http://www.nd.edu/~rwilliam * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/