We improved performance by using SpringJDBC's jdbcTemplate.batchUpdate (no Hibernate) and reserving a Sequence range in advance for any foreign keys.
We didn't get down to the level of actual N repeated INSERT statements, which the other poster referenced above did; we're still using a framework approach (JDBCTemplate), but at least we don't use Hibernate/ORM anymore. This approach is fast, but it's not as super-fast as the N repeated INSERTs -- but it's acceptable now.
The actual SpringJDBC Batch-Insert occurs via jdbcTemplate.batchUpdate(sqlInsert, new BatchPreparedStatementSetter() {..}, and we actually split up the batches ourselves -- the BatchPreparedStatementSetter won't automatically split anything up for us, it will just submit that particular batch with a predetermined size.
/**
* The following method performs a Native-SQL Batch-Insert of Participant accounts (using JdbcTemplate) to improve performance.
* Each Participant account requires 2 INSERTs: (1) USERS_T, (2) STUDY_PARTICIPANTS_T (with an FK reference to USERS_T.ID).
* Since there is no easy way to track the Sequence IDs between the two Batch-Inserts, we reserve the ID range for both tables, and
* then manually calculate our own IDs for USERS_T and STUDY_PARTICIPANTS_T ourselves.
* Initially, domain objects are filled out; then they are added to the Batch List that we submit and clear ourselves.
* (Originally the Batch-Insert was implemented with Hibernate/HQL, but due to slow performance it was nativized with jdbcTemplate.)
*
* NOTE: The entire method is @Transactional and all data will be rolled back in case of any exceptions in this method (rollbackFor=Exception.class).
* The updated Sequence values (set during reservation) will not be rolled back in this case, but Sequence gaps are normal.
*/
@Override
@Transactional(readOnly = false, rollbackFor = Exception.class)
public void createParticipantsAccounts(long studyId, List<String> subjectIds) throws Exception {
int maxInsertParticipantsBatchSize = 1000; // Batch size is 1000
/*
We need to insert into 2 tables, USERS_T and STUDY_PARTICIPANTS_T.
The table STUDY_PARTICIPANTS_T has an FK dependency on USERS_T.ID.
Since there is no easy way to track the Sequence IDs between the two Batch-Inserts, we reserve the ID range for both tables,
and then manually calculate our own IDs for USERS_T and STUDY_PARTICIPANTS_T ourselves.
The Sequences are immediately updated to the calculated final values to reserve the range.
*/
// 1. Obtain current Sequence values
Integer currUsersTSeqVal = userDAO.getCurrentUsersTSeqVal();
Integer currStudyParticipantsTSeqVal = studyParticipantsDAO.getCurrentStudyParticipantsTSeqVal();
// 2. Immediately update the Sequences to the calculated final value (this reserves the ID range immediately)
// In Postgres, updating the Sequences is: SELECT setval('users_t_id_seq', :val)
userDAO.setCurrentUsersTSeqVal(currUsersTSeqVal + subjectIds.size());
studyParticipantsDAO.setCurrentStudyParticipantsTSeqVal(currStudyParticipantsTSeqVal + subjectIds.size());
// List for Batch-Inserts, maintained and submitted by ourselves in accordance with our batch size
List<UsersT> batchInsertUsers = new ArrayList<UsersT>();
for(int i = 0; i < subjectIds.size(); i++) {
String subjectId = subjectIds.get(i);
// Prepare domain object (UsersT with associated StudyParticipantsT) to be used in the Native-SQL jdbcTemplate batchUpdate
UsersT user = new UsersT();
user.setId(currUsersTSeqVal + 1 + i); // Set ID to calculated value
user.setUsername(study.getAbbreviation().toUpperCase()+subjectId);
user.setActiveFlag(true);
// etc., fill out object, then subobject:
List<StudyParticipantsT> participants = new ArrayList<StudyParticipantsT>();
StudyParticipantsT sp = new StudyParticipantsT();
sp.setId(currStudyParticipantsTSeqVal + 1 + i); // Set ID to caculated value
// ...etc.
user.setStudyParticipantsTs(participants);
// Add to Batch-Insert List of Users
batchInsertUsers.add(user);
// If list size ready for Batch-Insert, or if at the end of all subjectIds, perform Batch Insert (both tables) and clear list
if (batchInsertUsers.size() == maxInsertParticipantsBatchSize || i == subjectIds.size() - 1) {
// Part 1: Insert batch into USERS_T
nativeBatchInsertUsers(jdbcTemplate, batchInsertUsers);
// Part 2: Insert batch into STUDY_PARTICIPANTS_T
nativeBatchInsertStudyParticipants(jdbcTemplate, batchInsertUsers);
// Reset list
batchInsertUsers.clear();
}
}
}
The sub-methods for the actual Batch-Insert:
/**
* Native-SQL Batch-Insert into USERS_T for Participant Upload.
* NOTE: This method is part of its Parent's @Transactional. (Note also that we need "final" on the List param for Inner-Class access to this variable.)
*
* @param jdbcTemplate
* @param batchInsertUsers
*/
private void nativeBatchInsertUsers(JdbcTemplate jdbcTemplate, final List<UsersT> batchInsertUsers) {
String sqlInsert = "INSERT INTO PUBLIC.USERS_T (id, password, user_name, created_by, created_date, last_changed_by, last_changed_date, " +
"first_name, last_name, organization, phone, lockout_date, lockout_counter, last_login_date, " +
"password_last_changed_date, temporary_password, active_flag, uuid, " +
"role_type_id, ws_account_researcher_id) " +
"VALUES (?, ?, ?, ?, ?, ?, ?, " +
"?, ?, ?, ?, ?, ?, ?, " +
"?, ?, ?, ?, " +
"?, ?" +
") ";
jdbcTemplate.batchUpdate(sqlInsert, new BatchPreparedStatementSetter() {
@Override
public int getBatchSize() {
return batchInsertUsers.size();
}
@Override
public void setValues(PreparedStatement ps, int i) throws SQLException {
ps.setInt(1, batchInsertUsers.get(i).getId()); // ID (provided by ourselves)
// etc., set PS for each i-th object
}
});
}
/**
* Native-SQL Batch-Insert into STUDY_PARTICIPANTS_T for Participant Upload.
* NOTE: This method is part of its Parent's @Transactional. (Note also that we need "final" on the List param for Inner-Class access to this variable.)
*
* @param jdbcTemplate
* @param batchInsertUsers
*/
private void nativeBatchInsertStudyParticipants(JdbcTemplate jdbcTemplate, final List<UsersT> batchInsertUsers) {
String sqlInsert = "INSERT INTO PUBLIC.STUDY_PARTICIPANTS_T (id, study_id, subject_id, user_id, locked, " + "created_by, created_date, last_changed_by, last_changed_date) " +
"VALUES (?, ?, ?, ?, ?, " +
"?, ?, ?, ? " +
") ";
jdbcTemplate.batchUpdate(sqlInsert, new BatchPreparedStatementSetter() {
@Override
public int getBatchSize() {
return batchInsertUsers.size();
}
@Override
public void setValues(PreparedStatement ps, int i) throws SQLException {
ps.setInt(1, batchInsertUsers.get(i).getStudyParticipantsTs().get(0).getId()); // ID (provided by ourselves)
// etc.
}
});
}
