select query inside loop - Database connections in JPA












1















In my Spring MVC application, I have @Transactional annotated method inside which I make call(select query) to DAO layer inside for loop.



If my input list size as "100" then I need to select 100 records from database. When the method inside the service layer is annotated with @Transactional, I thought selection of 100 records is a Unit of work and



I observe that each statement/call to DAO layer opens Connection.
I think it will impact the performance.



Questions :




  1. Is it possible to open the DB connection once and use the same till the end
    of all query(For Ex : 100 queries If the input list size is 100)?


  2. If I proceed in the current way of working will it be impacting the performance as it open the DB connection for every statements?



Service Implementation:



@Servive
public class MyServiceImpl implements MyService{

@Autowired
private MyDao myDao;

@Transactional
@Override
public List<Object> getRecords(Request req) {
List<String> inputList = new ArrayList<String>();
for(String input inputList) {
try {
Object recordFromDB = mydao.fetchRecordsFromDB(input);
} catch(NoResultFoundException e) {
LOGGER.error("NoResultException caught while making a call to DB TABLE1");
}
}
}
}


Dao Implementation:



@Repository
public class MyDaoImpl implements MyDao{

@PersistentContext
private EntityManager em;

@Override
public Object fetchRecordsFromDB(input ip) {
Query q = em.createNativeQuery("select col1, col2, col3 from TABLE1 where col = ?1 and col2 = ?2 and col3 = ?3");
Object recordsDB = null;
recordsDB = q.getSingleResult();
return recordsDB;
}
}


Logs :



As shown below DB connection is done for every statement.



09:35:56.815 TRACE o.h.i.SessionFactoryImpl$SessionBuilderImpl - Opening Hibernate Session.  tenant=null, owner=org.hibernate.jpa.internal.EntityManagerImpl@7bd18d
09:35:56.947 TRACE o.h.s.i.AbstractServiceRegistryImpl - Initializing service [role=org.hibernate.stat.spi.StatisticsImplementor]
09:35:56.954 DEBUG o.h.s.internal.StatisticsInitiator - Statistics initialized [enabled=false]
09:35:56.955 TRACE org.hibernate.internal.SessionImpl - Opened session at timestamp: 15427893568
09:35:56.963 TRACE org.hibernate.internal.SessionImpl - Setting flush mode to: AUTO
09:35:56.964 TRACE org.hibernate.internal.SessionImpl - Setting cache mode to: NORMAL
09:35:57.243 TRACE o.h.engine.query.spi.QueryPlanCache - Unable to locate native-sql query plan in cache; generating (SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1)
09:35:57.251 TRACE o.h.loader.custom.sql.SQLCustomQuery - Starting processing of sql query [SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1]
09:35:57.267 TRACE org.hibernate.internal.SessionImpl - SQL query: SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ? AND COL2 = ? AND ROWNUM = 1
09:35:57.285 DEBUG org.hibernate.SQL - _SELECT_COL1,COL2,_COL3 _FROM_TABLE1 _WHERE_COL1 = ? _AND COL2 = ? _AND ROWNUM = 1
09:35:57.444 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
09:35:57.445 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Registering last query statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
09:35:57.445 DEBUG org.hibernate.loader.Loader - bindNamedParameters() myValue2 -&gt; 2 [2]
09:35:57.452 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [ABC]
09:35:57.455 DEBUG org.hibernate.loader.Loader - bindNamedParameters() myValue1 -&gt; 1 [1]
09:35:57.455 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [1] as [VARCHAR] - [XYZ]
09:35:57.456 TRACE org.hibernate.loader.Loader - Bound [3] parameters total
09:35:57.521 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering result set [org.apache.commons.dbcp.DelegatingResultSet@17509f]
09:35:57.528 TRACE org.hibernate.loader.Loader - Processing result set
09:35:57.528 TRACE org.hibernate.loader.Loader - Done processing result set (0 rows)
09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing result set [org.apache.commons.dbcp.DelegatingResultSet@17509f]
09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing prepared statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
09:35:57.530 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Starting after statement execution processing [ON_CLOSE]
09:35:57.530 TRACE o.h.e.i.StatefulPersistenceContext - Initializing non-lazy collections
09:35:57.532 DEBUG o.s.o.jpa.EntityManagerFactoryUtils - Closing JPA EntityManager
09:35:57.532 TRACE org.hibernate.internal.SessionImpl - Closing session
09:35:57.532 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Closing JDBC container [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@1e6c7f5]
09:35:57.532 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
09:35:57.532 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Closing logical connection
09:35:57.535 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
09:35:57.535 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Logical connection closed
09:35:57.537 ERROR c.c.a.s.i.MyServiceImpl - ----NoResultException caught while making a call to DB TABLE1 javax.persistence.NoResultException: No entity found for query
09:35:57.538 DEBUG o.s.o.j.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler - Creating new EntityManager for shared EntityManager invocation
09:35:57.538 TRACE o.h.i.SessionFactoryImpl$SessionBuilderImpl - Opening Hibernate Session. tenant=null, owner=org.hibernate.jpa.internal.EntityManagerImpl@14d6023
09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Opened session at timestamp: 15427893575
09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Setting flush mode to: AUTO
09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Setting cache mode to: NORMAL
09:35:57.538 TRACE o.h.engine.query.spi.QueryPlanCache - Located native-sql query plan in cache (SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1)
09:35:57.538 TRACE org.hibernate.internal.SessionImpl - SQL query: SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ? AND COL2 = ? AND ROWNUM = 1
09:35:57.539 DEBUG org.hibernate.SQL - _SELECT_COL1,COL2,_COL3 _FROM_TABLE1 _WHERE_COL1 = ? _AND COL2 = ? _AND ROWNUM = 1
09:35:57.539 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
09:35:57.539 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Registering last query statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
09:35:57.539 DEBUG org.hibernate.loader.Loader - bindNamedParameters() val2-&gt; 2 [2]
09:35:57.539 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [val2]
09:35:57.540 DEBUG org.hibernate.loader.Loader - bindNamedParameters() val2-&gt; 1 [1]
09:35:57.542 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [1] as [VARCHAR] - [val1]
09:35:57.543 TRACE org.hibernate.loader.Loader - Bound [3] parameters total
09:35:57.549 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering result set [org.apache.commons.dbcp.DelegatingResultSet@1950c3f]
09:35:57.550 TRACE org.hibernate.loader.Loader - Processing result set
09:35:57.550 TRACE org.hibernate.loader.Loader - Done processing result set (0 rows)
09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing result set [org.apache.commons.dbcp.DelegatingResultSet@1950c3f]
09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing prepared statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
09:35:57.550 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Starting after statement execution processing [ON_CLOSE]
09:35:57.550 TRACE o.h.e.i.StatefulPersistenceContext - Initializing non-lazy collections
09:35:57.550 DEBUG o.s.o.jpa.EntityManagerFactoryUtils - Closing JPA EntityManager
09:35:57.550 TRACE org.hibernate.internal.SessionImpl - Closing session
09:35:57.550 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Closing JDBC container [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@570f5f]
09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
09:35:57.551 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Closing logical connection
09:35:57.551 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
09:35:57.552 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Logical connection closed
09:35:57.552 ERROR c.c.a.s.i.MyServiceImpl - ----NoResultException caught while making a call to DB TABLE1 furtherjavax.persistence.NoResultException: No entity found for query









share|improve this question





























    1















    In my Spring MVC application, I have @Transactional annotated method inside which I make call(select query) to DAO layer inside for loop.



    If my input list size as "100" then I need to select 100 records from database. When the method inside the service layer is annotated with @Transactional, I thought selection of 100 records is a Unit of work and



    I observe that each statement/call to DAO layer opens Connection.
    I think it will impact the performance.



    Questions :




    1. Is it possible to open the DB connection once and use the same till the end
      of all query(For Ex : 100 queries If the input list size is 100)?


    2. If I proceed in the current way of working will it be impacting the performance as it open the DB connection for every statements?



    Service Implementation:



    @Servive
    public class MyServiceImpl implements MyService{

    @Autowired
    private MyDao myDao;

    @Transactional
    @Override
    public List<Object> getRecords(Request req) {
    List<String> inputList = new ArrayList<String>();
    for(String input inputList) {
    try {
    Object recordFromDB = mydao.fetchRecordsFromDB(input);
    } catch(NoResultFoundException e) {
    LOGGER.error("NoResultException caught while making a call to DB TABLE1");
    }
    }
    }
    }


    Dao Implementation:



    @Repository
    public class MyDaoImpl implements MyDao{

    @PersistentContext
    private EntityManager em;

    @Override
    public Object fetchRecordsFromDB(input ip) {
    Query q = em.createNativeQuery("select col1, col2, col3 from TABLE1 where col = ?1 and col2 = ?2 and col3 = ?3");
    Object recordsDB = null;
    recordsDB = q.getSingleResult();
    return recordsDB;
    }
    }


    Logs :



    As shown below DB connection is done for every statement.



    09:35:56.815 TRACE o.h.i.SessionFactoryImpl$SessionBuilderImpl - Opening Hibernate Session.  tenant=null, owner=org.hibernate.jpa.internal.EntityManagerImpl@7bd18d
    09:35:56.947 TRACE o.h.s.i.AbstractServiceRegistryImpl - Initializing service [role=org.hibernate.stat.spi.StatisticsImplementor]
    09:35:56.954 DEBUG o.h.s.internal.StatisticsInitiator - Statistics initialized [enabled=false]
    09:35:56.955 TRACE org.hibernate.internal.SessionImpl - Opened session at timestamp: 15427893568
    09:35:56.963 TRACE org.hibernate.internal.SessionImpl - Setting flush mode to: AUTO
    09:35:56.964 TRACE org.hibernate.internal.SessionImpl - Setting cache mode to: NORMAL
    09:35:57.243 TRACE o.h.engine.query.spi.QueryPlanCache - Unable to locate native-sql query plan in cache; generating (SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1)
    09:35:57.251 TRACE o.h.loader.custom.sql.SQLCustomQuery - Starting processing of sql query [SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1]
    09:35:57.267 TRACE org.hibernate.internal.SessionImpl - SQL query: SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ? AND COL2 = ? AND ROWNUM = 1
    09:35:57.285 DEBUG org.hibernate.SQL - _SELECT_COL1,COL2,_COL3 _FROM_TABLE1 _WHERE_COL1 = ? _AND COL2 = ? _AND ROWNUM = 1
    09:35:57.444 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
    09:35:57.445 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Registering last query statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
    09:35:57.445 DEBUG org.hibernate.loader.Loader - bindNamedParameters() myValue2 -&gt; 2 [2]
    09:35:57.452 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [ABC]
    09:35:57.455 DEBUG org.hibernate.loader.Loader - bindNamedParameters() myValue1 -&gt; 1 [1]
    09:35:57.455 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [1] as [VARCHAR] - [XYZ]
    09:35:57.456 TRACE org.hibernate.loader.Loader - Bound [3] parameters total
    09:35:57.521 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering result set [org.apache.commons.dbcp.DelegatingResultSet@17509f]
    09:35:57.528 TRACE org.hibernate.loader.Loader - Processing result set
    09:35:57.528 TRACE org.hibernate.loader.Loader - Done processing result set (0 rows)
    09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
    09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing result set [org.apache.commons.dbcp.DelegatingResultSet@17509f]
    09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing prepared statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
    09:35:57.530 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Starting after statement execution processing [ON_CLOSE]
    09:35:57.530 TRACE o.h.e.i.StatefulPersistenceContext - Initializing non-lazy collections
    09:35:57.532 DEBUG o.s.o.jpa.EntityManagerFactoryUtils - Closing JPA EntityManager
    09:35:57.532 TRACE org.hibernate.internal.SessionImpl - Closing session
    09:35:57.532 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Closing JDBC container [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@1e6c7f5]
    09:35:57.532 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
    09:35:57.532 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Closing logical connection
    09:35:57.535 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
    09:35:57.535 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Logical connection closed
    09:35:57.537 ERROR c.c.a.s.i.MyServiceImpl - ----NoResultException caught while making a call to DB TABLE1 javax.persistence.NoResultException: No entity found for query
    09:35:57.538 DEBUG o.s.o.j.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler - Creating new EntityManager for shared EntityManager invocation
    09:35:57.538 TRACE o.h.i.SessionFactoryImpl$SessionBuilderImpl - Opening Hibernate Session. tenant=null, owner=org.hibernate.jpa.internal.EntityManagerImpl@14d6023
    09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Opened session at timestamp: 15427893575
    09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Setting flush mode to: AUTO
    09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Setting cache mode to: NORMAL
    09:35:57.538 TRACE o.h.engine.query.spi.QueryPlanCache - Located native-sql query plan in cache (SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1)
    09:35:57.538 TRACE org.hibernate.internal.SessionImpl - SQL query: SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ? AND COL2 = ? AND ROWNUM = 1
    09:35:57.539 DEBUG org.hibernate.SQL - _SELECT_COL1,COL2,_COL3 _FROM_TABLE1 _WHERE_COL1 = ? _AND COL2 = ? _AND ROWNUM = 1
    09:35:57.539 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
    09:35:57.539 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Registering last query statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
    09:35:57.539 DEBUG org.hibernate.loader.Loader - bindNamedParameters() val2-&gt; 2 [2]
    09:35:57.539 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [val2]
    09:35:57.540 DEBUG org.hibernate.loader.Loader - bindNamedParameters() val2-&gt; 1 [1]
    09:35:57.542 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [1] as [VARCHAR] - [val1]
    09:35:57.543 TRACE org.hibernate.loader.Loader - Bound [3] parameters total
    09:35:57.549 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering result set [org.apache.commons.dbcp.DelegatingResultSet@1950c3f]
    09:35:57.550 TRACE org.hibernate.loader.Loader - Processing result set
    09:35:57.550 TRACE org.hibernate.loader.Loader - Done processing result set (0 rows)
    09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
    09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing result set [org.apache.commons.dbcp.DelegatingResultSet@1950c3f]
    09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing prepared statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
    09:35:57.550 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Starting after statement execution processing [ON_CLOSE]
    09:35:57.550 TRACE o.h.e.i.StatefulPersistenceContext - Initializing non-lazy collections
    09:35:57.550 DEBUG o.s.o.jpa.EntityManagerFactoryUtils - Closing JPA EntityManager
    09:35:57.550 TRACE org.hibernate.internal.SessionImpl - Closing session
    09:35:57.550 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Closing JDBC container [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@570f5f]
    09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
    09:35:57.551 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Closing logical connection
    09:35:57.551 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
    09:35:57.552 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Logical connection closed
    09:35:57.552 ERROR c.c.a.s.i.MyServiceImpl - ----NoResultException caught while making a call to DB TABLE1 furtherjavax.persistence.NoResultException: No entity found for query









    share|improve this question



























      1












      1








      1


      2






      In my Spring MVC application, I have @Transactional annotated method inside which I make call(select query) to DAO layer inside for loop.



      If my input list size as "100" then I need to select 100 records from database. When the method inside the service layer is annotated with @Transactional, I thought selection of 100 records is a Unit of work and



      I observe that each statement/call to DAO layer opens Connection.
      I think it will impact the performance.



      Questions :




      1. Is it possible to open the DB connection once and use the same till the end
        of all query(For Ex : 100 queries If the input list size is 100)?


      2. If I proceed in the current way of working will it be impacting the performance as it open the DB connection for every statements?



      Service Implementation:



      @Servive
      public class MyServiceImpl implements MyService{

      @Autowired
      private MyDao myDao;

      @Transactional
      @Override
      public List<Object> getRecords(Request req) {
      List<String> inputList = new ArrayList<String>();
      for(String input inputList) {
      try {
      Object recordFromDB = mydao.fetchRecordsFromDB(input);
      } catch(NoResultFoundException e) {
      LOGGER.error("NoResultException caught while making a call to DB TABLE1");
      }
      }
      }
      }


      Dao Implementation:



      @Repository
      public class MyDaoImpl implements MyDao{

      @PersistentContext
      private EntityManager em;

      @Override
      public Object fetchRecordsFromDB(input ip) {
      Query q = em.createNativeQuery("select col1, col2, col3 from TABLE1 where col = ?1 and col2 = ?2 and col3 = ?3");
      Object recordsDB = null;
      recordsDB = q.getSingleResult();
      return recordsDB;
      }
      }


      Logs :



      As shown below DB connection is done for every statement.



      09:35:56.815 TRACE o.h.i.SessionFactoryImpl$SessionBuilderImpl - Opening Hibernate Session.  tenant=null, owner=org.hibernate.jpa.internal.EntityManagerImpl@7bd18d
      09:35:56.947 TRACE o.h.s.i.AbstractServiceRegistryImpl - Initializing service [role=org.hibernate.stat.spi.StatisticsImplementor]
      09:35:56.954 DEBUG o.h.s.internal.StatisticsInitiator - Statistics initialized [enabled=false]
      09:35:56.955 TRACE org.hibernate.internal.SessionImpl - Opened session at timestamp: 15427893568
      09:35:56.963 TRACE org.hibernate.internal.SessionImpl - Setting flush mode to: AUTO
      09:35:56.964 TRACE org.hibernate.internal.SessionImpl - Setting cache mode to: NORMAL
      09:35:57.243 TRACE o.h.engine.query.spi.QueryPlanCache - Unable to locate native-sql query plan in cache; generating (SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1)
      09:35:57.251 TRACE o.h.loader.custom.sql.SQLCustomQuery - Starting processing of sql query [SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1]
      09:35:57.267 TRACE org.hibernate.internal.SessionImpl - SQL query: SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ? AND COL2 = ? AND ROWNUM = 1
      09:35:57.285 DEBUG org.hibernate.SQL - _SELECT_COL1,COL2,_COL3 _FROM_TABLE1 _WHERE_COL1 = ? _AND COL2 = ? _AND ROWNUM = 1
      09:35:57.444 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
      09:35:57.445 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Registering last query statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
      09:35:57.445 DEBUG org.hibernate.loader.Loader - bindNamedParameters() myValue2 -&gt; 2 [2]
      09:35:57.452 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [ABC]
      09:35:57.455 DEBUG org.hibernate.loader.Loader - bindNamedParameters() myValue1 -&gt; 1 [1]
      09:35:57.455 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [1] as [VARCHAR] - [XYZ]
      09:35:57.456 TRACE org.hibernate.loader.Loader - Bound [3] parameters total
      09:35:57.521 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering result set [org.apache.commons.dbcp.DelegatingResultSet@17509f]
      09:35:57.528 TRACE org.hibernate.loader.Loader - Processing result set
      09:35:57.528 TRACE org.hibernate.loader.Loader - Done processing result set (0 rows)
      09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
      09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing result set [org.apache.commons.dbcp.DelegatingResultSet@17509f]
      09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing prepared statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
      09:35:57.530 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Starting after statement execution processing [ON_CLOSE]
      09:35:57.530 TRACE o.h.e.i.StatefulPersistenceContext - Initializing non-lazy collections
      09:35:57.532 DEBUG o.s.o.jpa.EntityManagerFactoryUtils - Closing JPA EntityManager
      09:35:57.532 TRACE org.hibernate.internal.SessionImpl - Closing session
      09:35:57.532 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Closing JDBC container [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@1e6c7f5]
      09:35:57.532 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
      09:35:57.532 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Closing logical connection
      09:35:57.535 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
      09:35:57.535 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Logical connection closed
      09:35:57.537 ERROR c.c.a.s.i.MyServiceImpl - ----NoResultException caught while making a call to DB TABLE1 javax.persistence.NoResultException: No entity found for query
      09:35:57.538 DEBUG o.s.o.j.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler - Creating new EntityManager for shared EntityManager invocation
      09:35:57.538 TRACE o.h.i.SessionFactoryImpl$SessionBuilderImpl - Opening Hibernate Session. tenant=null, owner=org.hibernate.jpa.internal.EntityManagerImpl@14d6023
      09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Opened session at timestamp: 15427893575
      09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Setting flush mode to: AUTO
      09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Setting cache mode to: NORMAL
      09:35:57.538 TRACE o.h.engine.query.spi.QueryPlanCache - Located native-sql query plan in cache (SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1)
      09:35:57.538 TRACE org.hibernate.internal.SessionImpl - SQL query: SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ? AND COL2 = ? AND ROWNUM = 1
      09:35:57.539 DEBUG org.hibernate.SQL - _SELECT_COL1,COL2,_COL3 _FROM_TABLE1 _WHERE_COL1 = ? _AND COL2 = ? _AND ROWNUM = 1
      09:35:57.539 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
      09:35:57.539 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Registering last query statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
      09:35:57.539 DEBUG org.hibernate.loader.Loader - bindNamedParameters() val2-&gt; 2 [2]
      09:35:57.539 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [val2]
      09:35:57.540 DEBUG org.hibernate.loader.Loader - bindNamedParameters() val2-&gt; 1 [1]
      09:35:57.542 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [1] as [VARCHAR] - [val1]
      09:35:57.543 TRACE org.hibernate.loader.Loader - Bound [3] parameters total
      09:35:57.549 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering result set [org.apache.commons.dbcp.DelegatingResultSet@1950c3f]
      09:35:57.550 TRACE org.hibernate.loader.Loader - Processing result set
      09:35:57.550 TRACE org.hibernate.loader.Loader - Done processing result set (0 rows)
      09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
      09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing result set [org.apache.commons.dbcp.DelegatingResultSet@1950c3f]
      09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing prepared statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
      09:35:57.550 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Starting after statement execution processing [ON_CLOSE]
      09:35:57.550 TRACE o.h.e.i.StatefulPersistenceContext - Initializing non-lazy collections
      09:35:57.550 DEBUG o.s.o.jpa.EntityManagerFactoryUtils - Closing JPA EntityManager
      09:35:57.550 TRACE org.hibernate.internal.SessionImpl - Closing session
      09:35:57.550 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Closing JDBC container [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@570f5f]
      09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
      09:35:57.551 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Closing logical connection
      09:35:57.551 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
      09:35:57.552 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Logical connection closed
      09:35:57.552 ERROR c.c.a.s.i.MyServiceImpl - ----NoResultException caught while making a call to DB TABLE1 furtherjavax.persistence.NoResultException: No entity found for query









      share|improve this question
















      In my Spring MVC application, I have @Transactional annotated method inside which I make call(select query) to DAO layer inside for loop.



      If my input list size as "100" then I need to select 100 records from database. When the method inside the service layer is annotated with @Transactional, I thought selection of 100 records is a Unit of work and



      I observe that each statement/call to DAO layer opens Connection.
      I think it will impact the performance.



      Questions :




      1. Is it possible to open the DB connection once and use the same till the end
        of all query(For Ex : 100 queries If the input list size is 100)?


      2. If I proceed in the current way of working will it be impacting the performance as it open the DB connection for every statements?



      Service Implementation:



      @Servive
      public class MyServiceImpl implements MyService{

      @Autowired
      private MyDao myDao;

      @Transactional
      @Override
      public List<Object> getRecords(Request req) {
      List<String> inputList = new ArrayList<String>();
      for(String input inputList) {
      try {
      Object recordFromDB = mydao.fetchRecordsFromDB(input);
      } catch(NoResultFoundException e) {
      LOGGER.error("NoResultException caught while making a call to DB TABLE1");
      }
      }
      }
      }


      Dao Implementation:



      @Repository
      public class MyDaoImpl implements MyDao{

      @PersistentContext
      private EntityManager em;

      @Override
      public Object fetchRecordsFromDB(input ip) {
      Query q = em.createNativeQuery("select col1, col2, col3 from TABLE1 where col = ?1 and col2 = ?2 and col3 = ?3");
      Object recordsDB = null;
      recordsDB = q.getSingleResult();
      return recordsDB;
      }
      }


      Logs :



      As shown below DB connection is done for every statement.



      09:35:56.815 TRACE o.h.i.SessionFactoryImpl$SessionBuilderImpl - Opening Hibernate Session.  tenant=null, owner=org.hibernate.jpa.internal.EntityManagerImpl@7bd18d
      09:35:56.947 TRACE o.h.s.i.AbstractServiceRegistryImpl - Initializing service [role=org.hibernate.stat.spi.StatisticsImplementor]
      09:35:56.954 DEBUG o.h.s.internal.StatisticsInitiator - Statistics initialized [enabled=false]
      09:35:56.955 TRACE org.hibernate.internal.SessionImpl - Opened session at timestamp: 15427893568
      09:35:56.963 TRACE org.hibernate.internal.SessionImpl - Setting flush mode to: AUTO
      09:35:56.964 TRACE org.hibernate.internal.SessionImpl - Setting cache mode to: NORMAL
      09:35:57.243 TRACE o.h.engine.query.spi.QueryPlanCache - Unable to locate native-sql query plan in cache; generating (SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1)
      09:35:57.251 TRACE o.h.loader.custom.sql.SQLCustomQuery - Starting processing of sql query [SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1]
      09:35:57.267 TRACE org.hibernate.internal.SessionImpl - SQL query: SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ? AND COL2 = ? AND ROWNUM = 1
      09:35:57.285 DEBUG org.hibernate.SQL - _SELECT_COL1,COL2,_COL3 _FROM_TABLE1 _WHERE_COL1 = ? _AND COL2 = ? _AND ROWNUM = 1
      09:35:57.444 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
      09:35:57.445 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Registering last query statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
      09:35:57.445 DEBUG org.hibernate.loader.Loader - bindNamedParameters() myValue2 -&gt; 2 [2]
      09:35:57.452 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [ABC]
      09:35:57.455 DEBUG org.hibernate.loader.Loader - bindNamedParameters() myValue1 -&gt; 1 [1]
      09:35:57.455 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [1] as [VARCHAR] - [XYZ]
      09:35:57.456 TRACE org.hibernate.loader.Loader - Bound [3] parameters total
      09:35:57.521 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering result set [org.apache.commons.dbcp.DelegatingResultSet@17509f]
      09:35:57.528 TRACE org.hibernate.loader.Loader - Processing result set
      09:35:57.528 TRACE org.hibernate.loader.Loader - Done processing result set (0 rows)
      09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
      09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing result set [org.apache.commons.dbcp.DelegatingResultSet@17509f]
      09:35:57.530 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing prepared statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@18e6f11]
      09:35:57.530 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Starting after statement execution processing [ON_CLOSE]
      09:35:57.530 TRACE o.h.e.i.StatefulPersistenceContext - Initializing non-lazy collections
      09:35:57.532 DEBUG o.s.o.jpa.EntityManagerFactoryUtils - Closing JPA EntityManager
      09:35:57.532 TRACE org.hibernate.internal.SessionImpl - Closing session
      09:35:57.532 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Closing JDBC container [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@1e6c7f5]
      09:35:57.532 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
      09:35:57.532 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Closing logical connection
      09:35:57.535 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
      09:35:57.535 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Logical connection closed
      09:35:57.537 ERROR c.c.a.s.i.MyServiceImpl - ----NoResultException caught while making a call to DB TABLE1 javax.persistence.NoResultException: No entity found for query
      09:35:57.538 DEBUG o.s.o.j.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler - Creating new EntityManager for shared EntityManager invocation
      09:35:57.538 TRACE o.h.i.SessionFactoryImpl$SessionBuilderImpl - Opening Hibernate Session. tenant=null, owner=org.hibernate.jpa.internal.EntityManagerImpl@14d6023
      09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Opened session at timestamp: 15427893575
      09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Setting flush mode to: AUTO
      09:35:57.538 TRACE org.hibernate.internal.SessionImpl - Setting cache mode to: NORMAL
      09:35:57.538 TRACE o.h.engine.query.spi.QueryPlanCache - Located native-sql query plan in cache (SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ?1 AND COL2 = ?2 AND ROWNUM = 1)
      09:35:57.538 TRACE org.hibernate.internal.SessionImpl - SQL query: SELECT COL1, COL2, COL3 FROM TABLE1 WHERE COL1 = ? AND COL2 = ? AND ROWNUM = 1
      09:35:57.539 DEBUG org.hibernate.SQL - _SELECT_COL1,COL2,_COL3 _FROM_TABLE1 _WHERE_COL1 = ? _AND COL2 = ? _AND ROWNUM = 1
      09:35:57.539 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
      09:35:57.539 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Registering last query statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
      09:35:57.539 DEBUG org.hibernate.loader.Loader - bindNamedParameters() val2-&gt; 2 [2]
      09:35:57.539 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [2] as [VARCHAR] - [val2]
      09:35:57.540 DEBUG org.hibernate.loader.Loader - bindNamedParameters() val2-&gt; 1 [1]
      09:35:57.542 TRACE o.h.type.descriptor.sql.BasicBinder - binding parameter [1] as [VARCHAR] - [val1]
      09:35:57.543 TRACE org.hibernate.loader.Loader - Bound [3] parameters total
      09:35:57.549 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Registering result set [org.apache.commons.dbcp.DelegatingResultSet@1950c3f]
      09:35:57.550 TRACE org.hibernate.loader.Loader - Processing result set
      09:35:57.550 TRACE org.hibernate.loader.Loader - Done processing result set (0 rows)
      09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
      09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing result set [org.apache.commons.dbcp.DelegatingResultSet@1950c3f]
      09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Closing prepared statement [oracle.jdbc.driver.OraclePreparedStatementWrapper@1db1a33]
      09:35:57.550 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Starting after statement execution processing [ON_CLOSE]
      09:35:57.550 TRACE o.h.e.i.StatefulPersistenceContext - Initializing non-lazy collections
      09:35:57.550 DEBUG o.s.o.jpa.EntityManagerFactoryUtils - Closing JPA EntityManager
      09:35:57.550 TRACE org.hibernate.internal.SessionImpl - Closing session
      09:35:57.550 TRACE o.h.e.j.internal.JdbcCoordinatorImpl - Closing JDBC container [org.hibernate.engine.jdbc.internal.JdbcCoordinatorImpl@570f5f]
      09:35:57.550 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
      09:35:57.551 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Closing logical connection
      09:35:57.551 TRACE o.h.r.j.i.ResourceRegistryStandardImpl - Releasing JDBC resources
      09:35:57.552 TRACE o.h.r.j.i.LogicalConnectionManagedImpl - Logical connection closed
      09:35:57.552 ERROR c.c.a.s.i.MyServiceImpl - ----NoResultException caught while making a call to DB TABLE1 furtherjavax.persistence.NoResultException: No entity found for query






      spring hibernate jpa jdbc transactions






      share|improve this question















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      share|improve this question




      share|improve this question








      edited Nov 21 '18 at 16:42







      Alagammal P

















      asked Nov 21 '18 at 14:51









      Alagammal PAlagammal P

      102518




      102518
























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