What do you mean the value is very large in t2? How large? What is it? You could put the large data in separate files on HDFS and just maintain a file name in the table.
> On 8. Apr 2018, at 19:52, Vitaliy Pisarev <vitaliy.pisa...@biocatch.com> > wrote: > > I have two tables in spark: > > T1 > |--x1 > |--x2 > > T2 > |--z1 > |--z2 > T1 is much larger than T2 > The values in column z2 are very large > There is a Many-One relationships between T1 and T2 respectively (via the x2 > and z1 columns). > I perform the following query: > > select T1.x1, T2.z2 from T1 > join T2 on T1.x2 = T2.z1 > In the resulting data set, the same value from T2.z2 will be multiplied to > many values of T1.x1. > > Since this value is very heavy- I am concerned whether the data is actually > duplicated or whether there are internal optimisations that maintain only > references? > > p.s > Originally posted on SO
