If Lens find the table is not a cube/dimension and pass the query through to drivers, then, how does Lens decide which driver to use? What if the driver picked is not the right one? For example, a query contains hive UDF is passed through to a MySQL database.
Thanks, On Wed, Aug 24, 2016 at 11:47 PM, Rajat Khandelwal <rajatgupt...@gmail.com> wrote: > That doesn't happen. One driver is picked to run the query. The drivers > bid by providing their estimate of cost for running this query. > > On Thu, Aug 25, 2016 at 1:47 AM Tao Yan <t...@linkedin.com> wrote: > >> If the query is executed in multiple drivers, and more than one drivers >> return the result, then, how does Lens decide which result to return to >> user? And if one driver return result before others, will Lens wait for >> other drivers? >> >> Thanks, >> >> On Wed, Aug 24, 2016 at 12:00 AM, Rajat Khandelwal < >> rajatgupt...@gmail.com> wrote: >> >>> Yes, it can be any standard sql. The logic in lens is to check the from >>> clause, and if the entity in the from-clause is either a cube or a >>> dimension, then treat it as cube query, and do the translation before >>> running this query. If it's not a cube or a dimension, it's treated as a >>> native query and all the drivers are forwarded this query as it is without >>> any translation. >>> >>> >>> On Wed, Aug 24, 2016 at 5:43 AM Tao Yan <t...@linkedin.com> wrote: >>> >>>> When using "select" (not "cube select"), can it be any standard SQL >>>> (not bounded to Lens QL)? >>>> >>>> Thanks! >>>> >>>> On Tue, Aug 23, 2016 at 4:57 PM, amareshwarisr . <amareshw...@gmail.com >>>> > wrote: >>>> >>>>> cube select expects the from clause to be on cube/dimension. select is >>>>> the one in SQL. >>>>> >>>>> Going forward from 2.6 onwards, cube keyword is optional for >>>>> cube/dimension queries. >>>>> >>>>> Thanks >>>>> >>>>> On Wed, Aug 24, 2016 at 3:53 AM, Tao Yan <t...@linkedin.com> wrote: >>>>> >>>>>> Hi Lens Developer, >>>>>> >>>>>> I found the following example in https://github.com/apache/ >>>>>> lens/blob/master/lens-examples/src/main/resources/ >>>>>> dimension-queries.sql >>>>>> >>>>>> select * from (cube select sample_dim.name name1, sample_dim2_chain. >>>>>> name name2 from sample_dim where sample_dim.name !='first') a >>>>>> >>>>>> I tested "cube select * " and it didn't work, and the above example >>>>>> shows "select *". What is the difference between "select" and "cube >>>>>> select"? >>>>>> >>>>>> Thanks, >>>>>> -- >>>>>> >>>>>> *Tao Yan* >>>>>> Software Engineer >>>>>> Data Analytics Infrastructure Tools and Services >>>>>> >>>>>> >>>>>> >>>>>> 206.250.5345 >>>>>> t...@linkedin.com >>>>>> https://www.linkedin.com/in/taousc >>>>>> >>>>> >>>>> >>>> >>>> >>>> -- >>>> >>>> *Tao Yan* >>>> Software Engineer >>>> Data Analytics Infrastructure Tools and Services >>>> >>>> >>>> >>>> 206.250.5345 >>>> t...@linkedin.com >>>> https://www.linkedin.com/in/taousc >>>> >>> >> >> >> -- >> >> *Tao Yan* >> Software Engineer >> Data Analytics Infrastructure Tools and Services >> >> >> >> 206.250.5345 >> t...@linkedin.com >> https://www.linkedin.com/in/taousc >> > -- *Tao Yan* Software Engineer Data Analytics Infrastructure Tools and Services 206.250.5345 t...@linkedin.com https://www.linkedin.com/in/taousc
