hi all, really appreciate the responses do you have any means as a work around for this ?
On Fri, Feb 14, 2014 at 4:22 PM, shashwat shriparv < dwivedishash...@gmail.com> wrote: > Because when you do select * the query just has to read and return the > resultl but when you give query under query suffle sort and comparison > happens thats why mapreduce... > > > *Warm Regards_**∞_* > * Shashwat Shriparv* > [image: > http://www.linkedin.com/pub/shashwat-shriparv/19/214/2a9]<http://www.linkedin.com/pub/shashwat-shriparv/19/214/2a9>[image: > https://twitter.com/shriparv] <https://twitter.com/shriparv>[image: > https://www.facebook.com/shriparv] <https://www.facebook.com/shriparv>[image: > http://google.com/+ShashwatShriparv] > <http://google.com/+ShashwatShriparv>[image: > http://www.youtube.com/user/sShriparv/videos]<http://www.youtube.com/user/sShriparv/videos>[image: > http://profile.yahoo.com/SWXSTW3DVSDTF2HHSRM47AV6DI/] <shrip...@yahoo.com> > > > > On Fri, Feb 14, 2014 at 4:15 PM, Nitin Pawar <nitinpawar...@gmail.com>wrote: > >> when you are writing a file, it will need an application to create and >> write the file. >> Thats why the mapreduce job to create the file. >> >> Where as for other way when its displayed on console, its just hdfs cat >> operation >> >> >> On Fri, Feb 14, 2014 at 4:13 PM, Sreenath <sreenaths1...@gmail.com>wrote: >> >>> i have two queries >>> 1. select * from tab1 limit 3; >>> this returns the 3 rows quickly withoput launcing any map reduce jobs; >>> >>> 2. INSERT OVERWRITE LOCAL DIRECTORY "/tmp/query1/" select * from tab1 >>> limit 3; >>> but the same above query to write to a local directory launches a map >>> reduce job and scans through all the rows launching map-reduce jobs >>> >>> why the differenceinexecution of both queries? >>> >>> -- >>> Sreenath S Kamath >>> Bangalore >>> Ph No:+91-9590989106 >>> >> >> >> >> -- >> Nitin Pawar >> > > -- Sreenath S Kamath Bangalore Ph No:+91-9590989106
