Best way to handle concurrency issues

Question

i have a LAPP (linux, apache, postgresql and php) environment, but the question is pretty the same both on Postgres or Mysql.

I have an cms app i developed, that handle

Answer 1

First off only update the fields that have changed on when writing to the database, this will decrease database load.

Second, query the timestamp of the last update, if you have a older timestamp then the current version in the database then throw the warning to the client.

Third is to somehow push this information to the client, though some kind of persistent connection with the server, enabling a concurrent two way connection.