Ah I see, looks like this is an open, tracked issue. See KUDU-1702 <https://issues.apache.org/jira/browse/KUDU-1702?jql=project%20%3D%20KUDU%20AND%20resolution%20%3D%20Unresolved%20AND%20text%20~%20%22read_at_snapshot%22%20ORDER%20BY%20priority%20DESC%2C%20updated%20DESC>, although not sure what the status on it is.
On Tue, Nov 28, 2017 at 12:17 PM, Mauricio Aristizabal < [email protected]> wrote: > Thanks very much David and Andrew. Yes I'm aware this functionality is > available via the java and C++ clients, but actually what I'm asking is if > it could be made available via SQL/impala. Something like "select X from Y > where snapshot_micros = 2343242423 <(234)%20324-2423>" (where > snapshot_micros is a virtual column that would need a better name), or > perhaps as part of the table name like "select X from Y@2343242423 > <(234)%20324-2423>". -m > > On Tue, Nov 28, 2017 at 12:05 PM, David Alves <[email protected]> > wrote: > >> Hi Mauricio >> >> Andrew is right. That feature already exists in some form. With >> READ_AT_SNAPSHOT you can provide a timestamp which will be the timepoint >> under which all the scans are performed. >> Note that, while generally supported and functionally tested, we >> haven't focused a lot of resources into testing this, so your performance >> mileage may vary. >> In order to enable this for time points more than 5 mins in the past >> you need to increase the "--tablet_history_max_age_sec" flag so that the >> history won't get garbage collected. >> >> HTH >> -david >> >> On Mon, Nov 27, 2017 at 9:42 PM, Andrew Wong <[email protected]> wrote: >> >>> Hi Mauricio, >>> >>> If you haven't already, take a look at the READ_AT_SNAPSHOT read mode >>> (more info here >>> <https://kudu.apache.org/docs/transaction_semantics.html#_read_operations_scans>). >>> IIUC, it seems similar to, if not exactly what you're looking for! >>> >>> >>> Andrew >>> >>> On Mon, Nov 27, 2017 at 5:02 PM, Mauricio Aristizabal < >>> [email protected]> wrote: >>> >>>> Hi all, has there been any talk of supporting this any time soon? >>>> >>>> Time travel reads are such a cool feature, but even more than in ETL >>>> jobs (via Java/Scala), they would be most useful via SQL to ensure >>>> consistency when reading. >>>> >>>> Specifically, for example our spark streaming job updates dozens of >>>> aggregation tables every 30 seconds. To make the data fully consistent we >>>> would love to have views over these aggs tagged with the exact timestamp we >>>> want to expose. When each batch is done and all tables updated, we would >>>> update all the views forward, effectively hiding the updates we're doing >>>> until they're all ready. >>>> >>>> -m >>>> >>>> >>>> >>>> -- >>>> *MAURICIO ARISTIZABAL* >>>> Architect - Business Intelligence + Data Science >>>> [email protected](m)+1 323 309 4260 <(323)%20309-4260> >>>> 223 E. De La Guerra St. | Santa Barbara, CA 93101 >>>> <https://maps.google.com/?q=223+E.+De+La+Guerra+St.+%7C+Santa+Barbara,+CA+93101&entry=gmail&source=g> >>>> >>>> Overview <http://www.impactradius.com/?src=slsap> | Twitter >>>> <https://twitter.com/impactradius> | Facebook >>>> <https://www.facebook.com/pages/Impact-Radius/153376411365183> | >>>> LinkedIn <https://www.linkedin.com/company/impact-radius-inc-> >>>> >>> >>> >>> >>> -- >>> Andrew Wong >>> >> >> > > > -- > *MAURICIO ARISTIZABAL* > Architect - Business Intelligence + Data Science > [email protected](m)+1 323 309 4260 <(323)%20309-4260> > 223 E. De La Guerra St. | Santa Barbara, CA 93101 > <https://maps.google.com/?q=223+E.+De+La+Guerra+St.+%7C+Santa+Barbara,+CA+93101&entry=gmail&source=g> > > Overview <http://www.impactradius.com/?src=slsap> | Twitter > <https://twitter.com/impactradius> | Facebook > <https://www.facebook.com/pages/Impact-Radius/153376411365183> | LinkedIn > <https://www.linkedin.com/company/impact-radius-inc-> > -- Andrew Wong
