Thanks Alan and just for double check: if I have the following script: 1) Create table tbl1, tbl2;
2) Select count(*) from tbl1 group by A; 3) Select count(*) from tbl2 groub by B; 4) Create table tb3; And this script will be executed exactly in 1 >2 > 3 > 4 order even 2 and 3 do not have relationship with each other and 4 does not have relation with all query 1,2,3? Xiaoyong From: Alan Gates [mailto:[email protected]] Sent: Thursday, December 18, 2014 8:05 AM To: Xiaoyong Zhu Cc: [email protected] Subject: Re: relationship between a hive query and a tez dag DDL operations are done from the client, not as part of a Tez DAG. There still is no linkage between the DAGs even if they access the same tables or somehow depend on each other. Hive manages making sure queries are executed in the order given. Tez just executed each query. Alan. [cid:[email protected]] Xiaoyong Zhu<mailto:[email protected]> December 16, 2014 at 15:41 Thanks Alan! Then what if different hive queries have some links (e.g. query 1 creates table abc and query 2 reads data from abc) will this be in 1 DAG or 2 DAGs? If 2, then is there any link/relatioinship between the 2 DAGs? Xiaoyong From: Alan Gates [mailto:[email protected]] Sent: Wednesday, December 17, 2014 5:27 AM To: [email protected]<mailto:[email protected]> Subject: Re: relationship between a hive query and a tez dag Several. Each Hive query becomes one Tez DAG. Alan. -- Sent with Postbox<http://www.getpostbox.com> 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. [cid:[email protected]] Alan Gates<mailto:[email protected]> December 16, 2014 at 13:26 Several. Each Hive query becomes one Tez DAG. Alan. -- Sent with Postbox<http://www.getpostbox.com> 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.
