extjs grid update on database change

Question

I need info about updating grid when database is changed.

What I have:
A client application in php which uses Extjs to provide interface to db.

What seems to be a problem:
A problem occurs when for example there are two users are using the app. The 1st user changes and commits data to db, the 2nd user isn't able to see the changed data.
Other example is when admin changes data directly in db.

What I'm trying to do:
I need to be able to load changed data to the grid in timely maner. Reloading store is an issue because the data returned is huge (takes few seconds to load) and while the app would be used by hundreds of users at one time it would create quite an overhead. Can I load only changed rows (can be checked by timestamp)?

Answer 1

There are 2 parts I see in this question:

Q) Can you update only the changed rows?

A) Sure. Find the record (using the store's "find" function), change the appropriate values (using record.set(key, value)) and commit the changes.

Q) Can you synchronize multiple users?

A) You have 2 options. Option #1, you can lock the object so only one user can edit at a time. This is the simplest solution. Option #2, you can add a synchronizing option (via comet would probably be the best option) and synchronize the changes as they occur.