Working with KB properties – Isolation Level

We faced a record lock issue some time back where our program was fetching values for a particular record from a transaction. If the record we were trying to read from, was open in Edit mode at the backend (AS/400), the procedure trying to read the data was getting aborted saying the Record has been locked (Java Front End). The easiest way to solve this issue was to change the Isolation Level property from Read Committed to Read Uncommitted.

Isolation Level Property in Java Web generator can be very useful for minimizing the Record Locks. GeneXus EV2 provides two types of Isolation Levels. 

1. Read Committed – The changes from one user are not available for the other users unless the changes are committed. So a transaction executing under this isolation level can only access the committed data. This is a default setting.

Pros: Data retrieved is consistent.

Cons: Can throw Record Locks and abort the process.

  

2. Read Uncommitted – The changes from one user are available for all users even if not committed. (This usually is a dirty read). So, if the first user updates some data, it can be read by other users even though first user can do the rollback of the read updates.

Pros: Quick performance, No record locks.

Cons: Data received may be inconsistent.

About GeneXus and this blog

GeneXus is developed in Montevideo Uruguay, in Artech's laboratories in Zonamerica
Business and Technology Park. It is a cross-platform 4GL tool that, starting from users' views, captures their knowledge and systematizes it in a Knowledge Base. Using this Knowledge Base, GeneXus automatically designs, generates and maintains the database structure and the application programs (the programs necessary for users to operate based on their own views.)

On this blog we are trying to consolidate various programming techniques and learning's we came across,  that can provide an ease of development. Stay tuned for more!