I am working on a php / mysql application that will handle a large amount of data - ideally more than 100,000 records so how is it to use memcache in this scenario.

How effective it is to use it and how much improvement can we observe by using memcache.

I’d suggest not to bother with memcached until you have some sort of baseline application working.

100,000 rows isn’t alot, so unless it represents a graph or something, MySql should be fine.

Depends how you use it, if you use it wrong, it can actually slow down your app.

I have a table which contains 200,000 records and I don’t consider that to be big. The table is in a database which runs on a shared host, and yet, I don’t encounter any issues when it comes to speed. 200,000 records is not enough to make a database even consider to start working, so I wouldn’t bother in trying to prematurely optimise the application, just use the database.

I always worry about performance when things are actually getting slow: I do however design my applications so that when there is a performance issue, I can solve it without changing all that many code.