As suggested, looking at the explain plan should tell you if map-join is getting used. Using a recent version with hive-on-tez would also give you further speedup as map-joins are optimized further in it.
On Tue, Mar 15, 2016 at 9:32 AM, sreebalineni . <sreebalin...@gmail.com> wrote: > You can think of map joins.If cluster is configured by default it must be > happening already check query profile > > On Tue, 15 Mar 2016 21:12 Himabindu sanka, <himabindu.sa...@gmail.com> > wrote: > >> Hi Team, >> >> >> >> I have a query where I am joining with 10 other entities >> >> >> >> Like >> >> >> >> Select a.col1,b1.col1,b2.col1 from >> >> >> >> A a >> >> Left outer join b1 on >> >> Left outer join b2 on >> >> Left outer join b3…. >> >> >> >> >> >> A is my driver entity which a 20 million data. Most of the other entities >> are small just 10 to 20 rows of data. >> >> >> In that scenario, my hive query is taking hours of time to join and fetch >> it. Please suggest me optimization technique. >> >> This is chocking the query performance. >> >> >> >> >> >> *Regards,* >> >> *Himabindu Sanka* >>