However, you may still want to benchmark its performance against a realistic volume of data. It may not solve your problem. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Asked 11 years, 11 months ago. Active 11 years, 11 months ago. Viewed 1k times. Even if the read and the write happen in separate database transactions like in the following example:.
Therefore, we can choose a short or smallint column type for the version property:. The short column takes 2 bytes and accommodates 65, possible values. So, with an average transaction of just 10 ms, it will take seconds before we hit the very same value we read previously, but which has been changed 65, times ever since. You must make sure that the Java version attribute and the database column type match perfectly.
So, if you are using a short primitive or Short Java object wrapper, then the database column must be smallint. However, in reality, the average transaction time is higher than 10 ms, and not every transaction wants to modify the same record we have previously read before. Therefore, the time it takes to modify an entity 65, times will take way more than seconds.
If you enjoyed this article, I bet you are going to love my Book and Video Courses as well. Using a short primitive type for the entity version property and a smallint column type on the database side is usually a much better choice than opting for an int or a long property. By using a more compact column type, we can save up space both on disk and in memory. This way, the database server can accommodate more entity records per in-memory page, so more rows can be ultimately stored in the buffer pool.
So, the best way to map an entity version property with JPA and Hibernate is to choose the right column type based on how often the entity is modified. Is there any hooks so that I can put my own implementation there. Thanks and Regards, Prasoon. Posted: Tue Jul 11, am. Well, I don't know if there is a solution in fact. IMO it doesn't seem normal that one of the column of a primary composite key could be null Did you put a primary key constraint of the columns in your db?
I just tried with Oracle 10G, it is impossible null primary key Posted: Fri Jan 05, pm. I'm having this same problem with a legacy database whose structure I cannot change. The table in question does not have a primary key, but does have a unique composite index which can be mapped as a key. BulkBeanException at com.
NullPointerException … 23 more. Exception in thread "main" org. NullPointerException at org. Can i make default zero value for version, so that what ever the operation is called like save or update, it will not raise the exception. Note: Remember friends, first we must run the logic to save the object then hibernate will inset 0 Zero. Presentation of concept is so lucid, eye-catching and cool, that i would love to learn all the concepts as soon as possible.
This version concept is required when multiple users using our application. Lets say two threads read the data. First thread update the data and then second thread update the data.
We lost the changes done by first thread. Simple way of explaining concepts. Like this tutorial site than others. Thanks java4s. Hibernate assumes that the id field starts out null on new objects and is assigned when they are first saved. So, howcome NULL gets saved in the database. Could you elaborate? Hi, I am getting issue in my app. Can you pls help me out. If you load any object, for second time onwards it will check in first level cache when call load.
Is it load method works fine or any exdception occurs what to do? What is exact use of versioning in hibernate? What is the use of knowing no. Please see the following steps and tell me where I am wrong, 1. Search any content 2.
Edit Entity 3. Save Entity and re-fetch for maintaining integrity 4. Same session again edit entity and save 5. Gives hibernate version mismatch. Thanks for providing this web site.
Main point in version is if any changes are done in existing data then only the version values is going to be change. MappingException: Unknown entity: versioning. So while creating table in DB through script initialized version column to its default for int 0. Now executing update.
So now column is not null this is zero it default value. Instead of using save first, executing update first with all other data for column. StaleObjectStateException: Row was updated or deleted by another transaction or unsaved-value mapping was incorrect : [com. Employee 1] at org.
Need ur help on this. I mean suppose 4 update has done on a particular object and I want to see all the update , update 1 ,update 2, …..
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