PostgreSQL not releasing locks from table

Question

We are migrating our application data from Oracle to PostgreSQL.

Environment Details:
Java 1.8
PostgreSQL 9.5 Enterprise Edition (XA DataSource)
Hibernate 4.3
WildFly 9.0.2

We are using latest PostgreSQL driver(postgresql-9.4.1212.jdbc42.jar) available on their website(https://jdbc.postgresql.org/download.html)

Edit: Also tried edb-jdbc17.jar driver which comes with postgres enterprise db. Still same result.

We have also set max_prepared_connections to 100 in postgresql.conf file.

The method given below is taking an object and using hibernate starting transaction and then committing the transaction. Method is not throwing any error or exception. But in database, the object is not getting saved and application is acquiring locks on the table which is resulting in deadlock. The same code works perfectly with Oracle.

public void createObject(Object obj) throws CSTransactionException {
    Session s = null;
    Transaction t = null;
    try {

        try {
            obj = performEncrytionDecryption(obj, true);
        } catch (EncryptionException e) {
            throw new CSObjectNotFoundException(e);
        }


        try{
            obj = ObjectUpdater.trimObjectsStringFieldValues(obj);
        }catch(Exception e){
            throw new CSObjectNotFoundException(e);
        }



        s = HibernateSessionFactoryHelper.getAuditSession(sf);
        t = s.beginTransaction();
        s.save(obj);
        t.commit();
        s.flush();
        auditLog.info("Creating the " + obj.getClass().getName().substring(obj.getClass().getName().lastIndexOf(".")+1) + " Object ");          
    } 
catch (PropertyValueException pve)
    {
        try {
            t.rollback();
        } catch (Exception ex3) {
            if (log.isDebugEnabled())
                log.debug("Authorization|||createObject|Failure|Error in Rolling Back Transaction|" + ex3.getMessage());
        }
        if (log.isDebugEnabled())
            log
                    .debug("Authorization|||createObject|Failure|Error in Rolling Back Transaction|" + pve.getMessage());
        throw new CSTransactionException(
                "An error occured in creating the " + StringUtilities.getClassName(obj.getClass().getName()) + ".\n" + " A null value was passed for a required attribute " + pve.getMessage().substring(pve.getMessage().indexOf(":")), pve);
    }
    catch (ConstraintViolationException cve)
    {
        try {
            t.rollback();
        } catch (Exception ex3) {
            if (log.isDebugEnabled())
                log.debug("Authorization|||createObject|Failure|Error in Rolling Back Transaction|" + ex3.getMessage());
        }
        if (log.isDebugEnabled())
            log
                    .debug("Authorization|||createObject|Failure|Error in Rolling Back Transaction|" + cve.getMessage());
        throw new CSTransactionException(
                "An error occured in creating the " + StringUtilities.getClassName(obj.getClass().getName()) + ".\n" + " Duplicate entry was found in the database for the entered data" , cve);
    }       
    catch (Exception ex) {
        log.error(ex);
        try {
            t.rollback();
        } catch (Exception ex3) {
            if (log.isDebugEnabled())
                log
                        .debug("Authorization|||createObject|Failure|Error in Rolling Back Transaction|"
                                + ex3.getMessage());
        }
        if (log.isDebugEnabled())
            log
                    .debug("Authorization|||createObject|Failure|Error in creating the "
                            + obj.getClass().getName()
                            + "|"
                            + ex.getMessage());
        throw new CSTransactionException(
                "An error occured in creating the "
                        + StringUtilities.getClassName(obj.getClass()
                                .getName()) + "\n" + ex.getMessage(), ex);
    } finally {
        try {

            s.close();
        } catch (Exception ex2) {
            if (log.isDebugEnabled())
                log
                        .debug("Authorization|||createObject|Failure|Error in Closing Session |"
                                + ex2.getMessage());
        }
    }
    if (log.isDebugEnabled())
        log
                .debug("Authorization|||createObject|Success|Successful in creating the "
                        + obj.getClass().getName() + "|");
}

Locks information from database:

Answer 1

You have to close the session after the commit (ideally in the finally block):

s = HibernateSessionFactoryHelper.getAuditSession(sf);
t = s.beginTransaction();
    try {
            s.save(obj);
            session.flush();
            session.clear();  
            t.commit(); 
            auditLog.info("Creating the " + obj.getClass().getName().substring(obj.getClass().getName().lastIndexOf(".")+1) + " Object ");          
        }        
    }catch (Exception e) {
        t.rollBack();
    }finally{
        s.close();
    }