Using PHP $_SESSION variable to store large amonts of data

I'm currently storing a fair amount of data in the $_SESSION variable. I'm doing this so I don't need to keep accessing the database.

Sho开发者_如何学JAVAuld I be worried about memory issues on a shared server?

Can servers cope with large amounts of data stored in the $_SESSION variable?

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Should I be worried about memory issues on a shared server?

Yes - session data is loaded into the script's memory on every request. Hence, you are at risk of breaking the individual per-script memory limit. Even if you don't hit the limit, this is really inefficient.

Accessing data from the database on demand is much better.

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.. in addition to what @Pekka wrote:

PHP sessions an not alternative to a caching solution !

You should investigate if your server has APC available. You should use that on top of layer which accesses information from database (assuming you actually have an OO code).