Hi
My application will potentially allow:
User 1 - read data from a customer table
User 2 - read same data from a customer table
User 1 - update a field
User 2 - update a field
It is possible User 2 is updating an out of date record (could be updating a different field, or indeed the same field)? Is there any way to prevent this from happening apart from insigating some field on every table that acts like a 'lock', by eg populating it with the sessionId of the first user to read that particular row (which seems very convoluted)?
My application services can be accessed through an
EJB layer. The application also requires the ability to be deployed outside a J2EE container, consequently transaction management has been set to 'CMT', with the transaction attribute set to 'NotSupported' (rollbacks & commits are explicitly set by calls to commit() & rollback() on the
jdbc connection) as mentioned
here. Can you provide any tips to help me in this concurrent access nightmare - I am sure I am not the firt person to come across this?