Posted by FrobinRobin on 09/16/07 14:37

Hi I need to create a list that is updated whenever a change occurs in
the database.
I first used Ajax to poll a part of the page and query the database
every 5-10 seconds, downloading the data every time... however as
someone pointed out.. polling is bad practice and uses a lot of
bandwidth.

I've given it some thought and I'm wondering whether I can use polling
more efficiently?

For example:
I have a function that querys the database and returns my results in a
structured array - I assign this as $current_list.
Then I poll a page that querys the database every 5-10 seconds and
compares $current_list against $new_list ... if there is a difference,
then it refreshes the $current_list array :)

As I'm refreshing the array on the server side and only downloading
when there is a change this should be much more bandwidth friendly
right?

Is there any point in only updating the part of the array which has
changed it's fairly small data (The array will have a max of ten
records (sub arrays) with 6 fields in each)

Many Thanks

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