@Mayur.. I don’t think the initial design considered CTAS for skewed tables. So it might not be supported at all.
@Lefty.. I am not sure where/how the docs are maintained. Is it version controlled? Or is it only maintained in confluence wiki? If it is the later can you please provide me access to edit the wiki? or alternatively if you can update the docs adding “stored as directories” to the examples, it will be great. Also updating the docs with “CTAS not supported for list bucketing”. Thanks Prasanth Jayachandran On Apr 26, 2014, at 8:03 AM, Mayur Gupta <mayur.gupt...@gmail.com> wrote: > Hey Prasanth, > > The CTAS for skewed table doesn't work, is it a bug? > > create tablet1(r1 string, r2 string) skewed by (r2) on (‘a’) stored as > directories select r1, r2 from t2; > > > On Thu, Apr 24, 2014 at 3:03 PM, Mayur Gupta <mayur.gupt...@gmail.com> wrote: > Thanks a lot Prasanth for the reply. I would have never figured that out as > the documentation at Hive Wiki DDL page and design page doesn't list this. > > One additional point it seems the Skewed table doesn't work when the table is > created as CTAS. The below statement doesn't create separate files. Is it a > bug or is it by intent? > > create tablet1(r1 string, r2 string) skewed by (r2) on (‘a’) stored as > directories select r1, r2 from t2; > > > On Thu, Apr 24, 2014 at 6:12 AM, Prasanth Jayachandran > <pjayachand...@hortonworks.com> wrote: > Hi Mayur, > > The reason why you see single file is, you have not enabled storing skewed > columns/values as directories. > You can do the following to enable storing the skewed columns and values as > directories > > set hive.mapred.supports.subdirectories=true; > set mapred.input.dir.recursive=true; > create tablet1(r1 string, r2 string) skewed by (r2) on (‘a’) stored as > directories; > > This will enable you to store the skewed columns as directories below > > /user/hive/warehouse/t1/r2=a/000000_0 (skewed values go here) > /user/hive/warehouse/t1/HIVE_DEFAULT_LIST_BUCKETING_DIR_NAME/000000_0 (all > other values go here) > > With respect to your desc extended question where skewedColValueLocationMaps > is empty, its a bug in implementation. I just verified that it shows empty > for unpartitioned tables. But it shows correctly for partitioned tables. > I have created a bug for unpartitioned tables here which you can track for > progress on this issue https://issues.apache.org/jira/browse/HIVE-6968 > > > Thanks > Prasanth Jayachandran > > On Apr 23, 2014, at 6:52 AM, Mayur Gupta <mayur.gupt...@gmail.com> wrote: > >> Below is my skewedInfo >> >> skewedInfo:SkewedInfo(skewedColNames:[r2], skewedColValues:[[a]], >> skewedColValueLocationMaps:{}) >> >> Any idea why is the skewedColValueLocationMaps empty? >> >> >> On Mon, Apr 21, 2014 at 11:19 AM, Mayur Gupta <mayur.gupt...@gmail.com> >> wrote: >> Hey There, >> >> I was trying to use Skewed tables but I am facing the issue that it is not >> creating separate files for the skewed data. Even with a simple example I am >> having the same issue. The hive version is 0.11. >> >> create table t(col1 string, col2 string); >> load data local inpath '/home/hadoop/a.txt' into table t; >> >> create table t1(r1 string, r2 string) skewed by (r2) on ('a'); >> insert into table t1 select * from t; >> >> The contents of a.txt are : >> 1 ^Aa >> 2^A b >> 3 ^Ac >> 4 ^Aa >> 5 ^Ab >> 6 ^Aa >> >> I see only single file. >> >> /user/hive/warehouse/t1/000000_0 >> >> Any pointers on what I am doing wrong? >> > > > CONFIDENTIALITY NOTICE > NOTICE: This message is intended for the use of the individual or entity to > which it is addressed and may contain information that is confidential, > privileged and exempt from disclosure under applicable law. If the reader of > this message is not the intended recipient, you are hereby notified that any > printing, copying, dissemination, distribution, disclosure or forwarding of > this communication is strictly prohibited. If you have received this > communication in error, please contact the sender immediately and delete it > from your system. Thank You. > > -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
