transactions

问题 I am using sqlite c/c++ interface. I have 3 tables (related tables) say A, B, C. Now, there is a function called Set , which get some inputs and based on the inputs inserts rows into these three tables. (sometimes it can be an update in one of the tables) Now I need two things. One, i dont want autocommit feature. Basically I would like to commit after every 1000 calls to Set function Secondly, within the set function itself, if i find that after inserting into two tables, the third insert

问题 I've been reading that some devs/dbas recommend using transactions in all database calls, even read-only calls. While I understand inserting/updating within a transaction what is the benefit of reading within a transaction? 回答1: So you get a consistent view of the database. Imagine you have two tables that link to each other, but for some reason you do 2 selects... in pseuodocode: myRows = query(SELECT * FROM A) moreRows = query(SELECT * FROM B WHERE a_id IN myRows[id]) If between the two

问题 I am using Spring 3, JPA + Hibernate for a CMS application. In that application I have a service class method which is annotated with @Transactional Annotation with rollBack property. Inside that method I am inserting data (ie entity classes) to a table using a loop. For each iteration of the loop entity classes has to be saved to the database. But it is not happening. The commit only happens when the execution of the loop has completed and exits from the method. Then it commits and saves all

问题 Below is the statement written from Wikipedia's Isolation article about REPEATABLE READS In this isolation level, a lock-based concurrency control DBMS implementation keeps read and write locks (acquired on selected data) until the end of the transaction. However, range-locks are not managed, so the phantom reads phenomenon can occur (see below). My question here is when does the the transaction begin and end respectively. If we take the example of Non-repeatable reads with REPEATABLE READS

问题 I am developing a J2EE application which is deployed on JBoss application server. The application is composed of an EJB 2.x component and a web component and is running on local computer or remote server. The database is either Oracle or SQL Server and is not in a distributed envrionment. I am using Hibernate 3.6 (JPA 2.0 implementation) for the transactions. Should I use JTA which is container managed transaction or is it overkilled to use it? Currently I am using JTA and it turns out it is

问题 I have a stored procedure that has a BEGIN TRANSACTION and COMMIT TRANSACTION statement. Within the transaction is a select query WITH(XLOCK, ROWLOCK) . The transaction can potentially fail due to some calculations that cause an arithmetic overflow error if out of bounds values are supplied. This error would happen before any insert/update statements. My question is, should I wrap the transaction in a TRY/CATCH and rollback or is this not really required and all locks would be released

问题 I'm looking for some opinions here, I'm building a web application which has the fairly standard functionality of: Register for an account by filling out a form and submitting it. Receive an email with a confirmation code link Click the link to confirm the new account and log in When you send emails from your web application, it's often (usually) the case that there will be some change to the persistence layer. For example: A new user registers for an account on your site - the new user is

问题 I have hosted my Webapp on server 1 and my database on server 2 But i m getting following error "Communication with the underlying transaction manager has failed." I googled and found a post which mentioned that it is the issue of DTC(Distributed Transaction) I enabled DTC on server2(DB server) and made an exception of it in Firewall. But still same error. Here is the full stack trace Message: System.Transactions.TransactionManagerCommunicationException: Communication with the underlying

问题 Are Java EE 6 CDI events transactional? If I fire an event in a transaction, and subsequently roll back the transaction, are the effects of the Event listener rolled back as well? Is this behaviour dependent on the event listener itself supporting transactions? What about if I try and roll-back the exception from within then event listener, does it roll-back the transaction that fired the event? 回答1: From the events chapter of the CDI 1.0 specification, one can define an event to be

问题 Can I do? Start transaction; insert into db1.table1 (field1) values (100),(100); insert into db2.table2 (field2) values (100),(100); commit; Or will that not work? 回答1: Yes you can: MySQL 5.0.3 and up provides server-side support for XA transactions. Currently, this support is available for the InnoDB storage engine. The MySQL XA implementation is based on the X/Open CAE document Distributed Transaction Processing: The XA Specification. This document is published by The Open Group and