As a user, I think impala should always turn this feature on. 2017-05-05 14:57 GMT+08:00 Alexander Behm <[email protected]>:
> 1. For my understanding, what's the use case for turning this feature on > and off? Why not have it on all the time? > > 2. A query/session option seems awkward because Impala loads the block > metadata in the catalogd and caches it. How would an impalad know if there > is already sufficient metadata in the cache? Should we reload the table > metadata whenever such a SET option is used? I'm thinking of a table that > does not have data in subdirectories. You could add an additional "loading > state" to a table to indicate whether it was loaded with/without > subdirectories. Overall this solution does not seem to fit very well into > the existing architecture, and sounds overly complicated. > > 3. A table property is more consistent with the existing architecture. > > On Thu, May 4, 2017 at 11:03 PM, Shant Hovsepian <[email protected]> > wrote: > > > Hi All, what are people's thoughts on IMPALA-4726 > > <https://issues.apache.org/jira/browse/IMPALA-4726> and IMPALA-4596 > > <https://issues.apache.org/jira/browse/IMPALA-4596>? These are > concerning > > support for recursing through subdirectories in a table location to > search > > for all data files. > > > > Restricting the behavior to external tables only seems like a good idea, > > but as for turning on the behavior what are thoughts around making it a > > runtime session setting with "SET" like hive does, or potentially making > it > > something permanent like a table property. > > > > Thanks! > > > > -Shant > > >
