Re: [R] Suggestion for big files [was: Re: A comment about R:]

From: hadley wickham <>
Date: Fri 06 Jan 2006 - 18:28:27 EST

> Selecting a sample is easy. Yet, I'm not aware of any SQL device for
> easily selecting a _random_ sample of the records of a given table. On
> the other hand, I'm no SQL specialist, others might know better.

There are a number of such devices, which tend to be rather SQL variant specific. Try googling for select random rows mysql, select random rows pgsql, etc.

Another possibility is to generate a large table of randomly distributed ids and then use that (with randomly generated limits) to select the appropriate number of records.

Hadley mailing list PLEASE do read the posting guide! Received on Fri Jan 06 18:39:09 2006

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