Check if 1/3 Queries Evaluates to True
Make sure t3.x is indexed.

If you know one test is much cheaper than another, it may be faster to JOIN them in a manner that makes sense, then use the /*+ORDERED*/ hint to force the optimizer to join them in the order you've written them. This is particularly necessary if your inner query contains REGEX expressions since the optimizer prefers to procrastinate evaluating them.