Thanks Alan. My Hive is version 2 transactional and its metastore is on Oracle.
I saw this note <https://cwiki.apache.org/confluence/display/Hive/Hive+Transactions> stating .....Using Oracle as the Metastore DB and "datanucleus.connectionPoolingType=BONECP" may generate intermittent "No such lock.." and "No such transaction..." errors. Setting "datanucleus.connectionPoolingType=DBCP" is recommended in this case.... So I changed the setting to DBCP. Don't know how useful it is going to be. Regards, Dr Mich Talebzadeh LinkedIn * https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw <https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw>* http://talebzadehmich.wordpress.com On 26 May 2016 at 00:05, Alan Gates <alanfga...@gmail.com> wrote: > It’s depends on how it’s configured. In $HIVE_HOME/conf/hive-site.xml you > can set the datanucleus.connectionPoolingType variable to BONECP or DBCP. > By default it should be using BONECP I believe. (I think NONE is also a > valid value, but that doesn’t yet work with ACID turned on.) > > Alan. > > > On May 25, 2016, at 13:03, Mich Talebzadeh <mich.talebza...@gmail.com> > wrote: > > > > > > Hi, > > > > > > I am sure someone knows the answer to this question. > > > > Does Hive 2.0 use connection pool to connect to its metastore? I see a > lot of open and closed connections to the metastore that may not be > necessary. > > > > A connection pool is a cache of database connection objects. Connection > pools promote the reuse of connection objects and reduce the number of > times that connection objects are created. Connection pools significantly > improve performance for database-intensive applications because creating > connection objects is costly both in terms of time and resources. > > > > Thanks > > > > Dr Mich Talebzadeh > > > > LinkedIn > https://www.linkedin.com/profile/view?id=AAEAAAAWh2gBxianrbJd6zP6AcPCCdOABUrV8Pw > > > > http://talebzadehmich.wordpress.com > > > >
