Hello Elliot, Thanks for clarification.
But I am still not able to understand the hive working. My cluster has following properties. Txn.manager- dummyTxnManager Cocurrency - true Actually I am trying to insert data into two different partitions of a table at the same time. When I check the locks present on the table ,it shows the shared lock.Which does not allow the writes on the table. So I wanted to understand that , Does hive execute these two insert operations sequentially or it executes it in parallel . Thanks, Suyog On Aug 23, 2015 4:23 PM, "Elliot West" <tea...@gmail.com> wrote: > Shared locks are all that is required to insert data into transactional > tables. Multiple clients can hold a shared lock simultaneously. Each client > will write using uniquely assigned transaction ids so that their work is > isolated from one another. It should actually be possible for multiple > clients to insert into the same partition concurrently. > > See slide 12 in: > http://www.slideshare.net/mobile/Hadoop_Summit/w-525210-comalley > > Thanks - Elliot. > > On Friday, 21 August 2015, Suyog Parlikar <suyogparli...@gmail.com> wrote: > >> Thanks Elliot, >> >> For the immediate reply. >> >> But as per hive locking mechanism, >> While inserting data to a partition hive acquires exclusive lock on that >> partition and shared lock on the entire table. >> >> How is it possible to insert data into a different partition of the same >> table while having shared lock on the table which does not allow write >> operation. >> >> Please correct me if my understanding about the same is wrong. >> (I am using hql inserts only for these operations) >> >> Thanks, >> Suyog >> On Aug 21, 2015 7:28 PM, "Elliot West" <tea...@gmail.com> wrote: >> >>> I presume you mean "into different partitions of a table at the same >>> time"? This should be possible. It is certainly supported by the streaming >>> API, which is probably where you want to look if you need to insert large >>> volumes of data to multiple partitions concurrently. I can't see why it >>> would not also be possible with HQL INSERTs. >>> >>> On Friday, 21 August 2015, Suyog Parlikar <suyogparli...@gmail.com> >>> wrote: >>> >>>> Can we insert data in different partitions of a table at a time. >>>> >>>> Waiting for inputs . >>>> >>>> Thanks in advance. >>>> >>>> - suyog >>>> >>>
