https://community.cloudera.com/t5/Support-Questions/merge-csv-files-based-on-a-column-timestamp-to-get-one-file/m-p/136343#M98992 <P>Sol 1: Reduce side join</P><P>create separate mappers for all 4 csv files and produce the time stamp as key from all mappers and remaining fields + tag field to represent from which file it is returned as value. </P><P>handle them in reduce side..</P><P>Sol 2: Map side join (if 3 files are small)</P><P>add 3 csv files into distributed cache and merge them with large csv file in mapper.</P> Fri, 03 Mar 2017 22:51:18 GMT balaram38489 2017-03-03T22:51:18Z