Understanding Transactions And Locking In PostgreSQL
In most modern relational databases there is support for concurrent operations. PostgreSQL is no different.
While concurrency can drastically improve the performance of your application it also has many different implications to thread safety.
For those of you who are not familiar with thread safety in general terms; thread safety is the process of ensuring that two threads cannot do the same operation at the same time.
The following article discusses transaction control and table locking in PostgreSQL and is intended for an advanced audience.