You are getting the error because you are ORDERing BY rank but rank is not in the top SELECT
Also, DISTRIBUTE BY/SORT BY are done after SELECT so you have to use a subquery: SELECT ..., rank(user) FROM (SELECT ... DISTRIBUTE BY ... SORT BY) igor decide.com On Tue, Apr 2, 2013 at 10:03 AM, Keith Wiley <kwi...@keithwiley.com> wrote: > On Apr 1, 2013, at 16:12 , Alexander Pivovarov wrote: > > > > http://ragrawal.wordpress.com/2011/11/18/extract-top-n-records-in-each-group-in-hadoophive/ > > Is there any possibility there is a bug in Ritesh Agrawal's query > statement from that article? I created a test table with the exact column > names from the example in the article and used a minimally altered version > of the command (I removed the where clause to simplify things a bit) and > got an error which suggests there is something slightly wrong with the > command (or perhaps the table has to be configured a special way). Here's > what I get when I almost perfectly duplicate that example: > > hive> describe test; > OK > user string > category string > value int > Time taken: 0.082 seconds > ================================================== > hive> select * from test; > OK > user1 cat1 1 > user1 cat1 2 > user1 cat1 3 > user1 cat2 10 > user1 cat2 20 > user1 cat2 30 > user2 cat1 11 > user2 cat1 21 > user2 cat1 31 > user2 cat2 5 > user2 cat2 6 > user2 cat2 7 > Time taken: 0.202 seconds > ================================================== > hive> SELECT user, category, value > > FROM ( > > SELECT user, category, rank(user) as rank, value > > FROM test > > DISTRIBUTE BY user > > SORT BY user, value desc > > ) a > > WHERE rank > 1 > > ORDER BY user, rank; > FAILED: Error in semantic analysis: Line 9:15 Invalid table alias or > column reference 'rank': (possible column names are: _col0, _col1, _col2) > hive> > > > ________________________________________________________________________________ > Keith Wiley kwi...@keithwiley.com keithwiley.com > music.keithwiley.com > > "What I primarily learned in grad school is how much I *don't* know. > Consequently, I left grad school with a higher ignorance to knowledge > ratio than > when I entered." > -- Keith Wiley > > ________________________________________________________________________________ > >
