But consider one thing...

Why we go for those kinds of massive libraries or classes or over generalize things, for a DB migration.

I Accept PEAR, Smarty and DBObjects are widely libraries in PHP. But how it increases the web site capabilities?

Just have a look this bellow link how the generalized libraries affect your web site performance.

Mike Morgan - morgamic.com » Blog Archive » Scalable PHP with APC, memcached and LVS (Part 2)