Some operations like map, filter, flatMap and coalesce (with shuffle=false) usually preserve the order. However, sortBy, reduceBy, partitionBy, join etc. do not.

Regards,
_________________________________

Md. Rezaul Karim, BSc, MSc
PhD Researcher, INSIGHT Centre for Data Analytics
National University of Ireland, Galway

IDA Business Park, Dangan, Galway, Ireland

Web: http://www.reza-analytics.eu/index.html

On 27 January 2017 at 09:44, Soheila S. <soheila518@gmail.com> wrote:

Hi All,
I read a test file using sparkContext.textfile(filename) and assign it to an RDD and process the RDD (replace some words) and finally write it to a text file using rdd.saveAsTextFile(output).
Is there any way to be sure the order of the sentences will not be changed? I need to have the same text with some corrected words.

thanks!

Soheila