I have used both jdbcTemplate and Hibernate, but I am having a hard time comparing jdbcTemplate and hibernate in the context of performance, query execution time and batch updates.
My View and research did so far.
As hibernate uses HQL then its query is first translated into native language query and after that query is executed. So query execution time is high in case of hibernate(that's a different case as hibernate also support native query).
As Hibernate is ORM tool so we don't have to create the DataBase schema.
The batch insert of records is not piece of cake in hibernate as if the generation type of PK is Identity then batch insert won't be performed.
Is there are any other point when comparing JDBCTemplate and hibernate and when to use what?
Related
I have usually JpaRepository.
There are several types of queries in it.
made with
JPA
JPQL
HQL
It occurred to me to see if they were doing unnecessary actions. I have enabled SQL query debug. Requests began to be output to my console.
I want to write a test for queries so that they do not contain join when it is not needed.
How can I get the string that Hibernate (or Spring Data JPA) generates.
Maybe there are other ways to find such dangerous situations in the code?
In Hibernate Envers it is possible to have a separate audit table. Similarly, is it possible to log into tables other than the entity’s table using Spring Data JPA auditing?
The auditing feature of Spring Data JPA just fills attributes in the entity you are persisting. How and where these attributes get persisted is controlled by you JPA implementation and of course your database.
JPA offers #SecondaryTable to map fields to a second table.
If this isn't flexible enough for you, you can always employ database tools to achieve the effect by mapping the entity to a view which via triggers distributes the data however you want.
I am using a Spring Data Repository interface to retrieve data from DB2 (z/OS). I have a couple of methods that rely on the method signatues and one that relies on an explicit #Query.
How do I make the SQL generated have the "WITH UR" clause?
I added #Transactional(isolation=Isolation.READ_UNCOMMITTED) on the line above the #Query annotation and also above the two methods but it doesn't seem to append the clause to the generated SQL.
Thanks
I have a requirement where I have to insert a row into the Database and get the Key (Identity) back. I thought of using SimpleJdbcInsert for this. I am passing the Object of JdbcTemplate to my SimpleJdbcInsert and executing method executeAndReturnKey().
The same can be done using update() method of JdbcTemplate by setting PreparedStatement instead of Parameters Map.
I just want to know if JdbcTemplate is better in terms of performance and should I be using it over SimpleJdbcInsert? If so then what is the reason for it's superior performance?
Note: I'm not inserting a Batch of Records but a single record only.
Thanks
SimpleJdbcInsert vs JdbcTemplate
From docs.spring.io
JdbcTemplate is the classic Spring JDBC approach and the most popular. This "lowest level" approach and all others use a JdbcTemplate under the covers.
Note :all others use a JdbcTemplate under the covers
SimpleJdbcInsert optimize database metadata to limit the amount of necessary configuration. This approach simplifies coding so that you only need to provide the name of the table or procedure and provide a map of parameters matching the column names. This only works if the database provides adequate metadata. If the database doesn’t provide this metadata, you will have to provide explicit configuration of the parameters.
If you are going to use A SimpleJdbcInsert,then also the actual insert is being handled using JdbcTemplate. So definitely in terms of performance SimpleJdbcInsert can not be better that JdbcTemplate.
So performance wise you can not be beneficial using SimpleJdbcInsert.
But perform insert operations in to multiple tables by using SimpleJdbcInsert is having definitely better capability then JdbcTemplate class.There may be some situation in which you want to insert data in lot of tables and you may like to do less coding.In these situations, using of SimpleJdbcInsert can be a very good option.See this example to understand that.
JPA #NamedQuery is translated to SQL only once when application is deployed and generated SQL is cached.
EntityManager.createQuery translates query every time our method is called.
What Spring-data-jpa is doing with query defined in #Query annotation? Is it translated to SQL once during deployment (like NamedQuery) or translated every time (like dynamic query) ?
Spring Data JPA calls EntityManager.createQuery(…) for every invocation of a query method annotated with #Query. The reason for that is quite simple: the Query instances returned by the EntityManager are not thread-safe and actually stateful as they contain bound parameter information.
That said, most of the JPA persistence provider perform some kind of text-based query caching anyway so that they basically build the actual SQL query once for a certain JPQL query and reuse the former on subsequent invocations.
As an interesting side note, when we started building the support for #Query in 2008 we looked into possibilities to rather register the manually declared queries as named queries with JPA. Unfortunately there wasn't - and up until today - there's no way to manually register a named query programmatically via the JPA.